Hungarian GP 2011: as it happened

12.45pm BST Hello and welcome to forumula1.com’s live coverage of the Hungarian Grand Prix.

Quite apart from the metaphorical cloud hanging over the sport in the form of the Sky TV deal, there are literal clouds over the Hungaroring. More pressingly, perhaps, they are actually leaking water from the sky.

So it’s light, at the moment, and so it should be intermediate that most of the drivers opt for. It would be a brave man who went for full wets, even though more rain is forecast.

Ross Brawn tells the BBC the key decision will be when to go onto dries, as he doesn’t believe the foretold rain will actually arrive. He also says that Schumacher, ninth on the grid, is struggling with the balance of the car.

Sebastian Vettel starts from pole position, but it will be Button from third whom he will be keeping an eye on in these conditions, in which the Englishman usually excels. It’s Button’s 200th start, today, of course, at the track where he won his first GP in 2006.

“We’re most worried about Fernando Alonso,” Christian Horner casually blows my theory out the water. “Reading the weather is going to be crucial…it’s going to be fascinating. Conditions are changing every five minutes.”

The Safety Car is out on its lap to inspect the circuit. It is damp, but not properly wet. Greasy.

12.55pm The grid is now being cleared.

And they’re off on the installation lap, as the FIA graphic tells us that the top ten are all on inters. “No heroics,” Force India tell Adrian Sutil. “Stay on the road and you’ll score scme good points today.” As if to confirm the tricky nature of the track, Nico Rosberg takes a minor detour. No harm done.

They are now lining up on the grid.

1pm And they’re off! Down to the first turn, the hairpin! It’s Vettel who leads! And the McLarens are battling through turns two and three! Lewis stays ahead just!

The Mercedes cars have had a great start! The Ferraris have lost out! Everybody is very squirmy and twitchy, there is not much grip AT ALL. Alonso passes Schumacher for fifth.

Lap2 It’s Vettel, Hamulton, Button…but Hamilton is right on Vettel’s tail!! For the lead! Vettel repels him. Fourth is Rosberg, fifth Alonso, sixth Schumacher, seventh Massa, eighth Webber.

Lap 3 And Hamilton is right on Vettel again through turns two and three! This is fascinating action here. And Alonso is past Rosberg and Massa is past Schumacher, somewhat restoring the natural order of things.

Lap 4 And Alonso, who was hounding Button, overcooked it in three and left the track. He rejoins behind Rosberg. Hamilton is still harrying Vettel. A dry line is emerging but it is mighty slippy off that line.

Lap 5 Vettel has made a mistake into two! And Hamilton’s through…and will Button also be? Vettel’s error was the same as Alonso made last time round and that is crucial.

Lap 6 “Use the yellow button to overtake Vettel,” McLaren urge Button. Engine mode? wonder the BBC commentators. The order is now Hamilton, Vettel, Button, Rosberg, Alonso, Massa, Webber, Schumacher, di Resta, Kobayashi, Petrov, Buemi, Barrichello, Alguersuari, Maldonado.

Lap 7 Alonso went off again last lap but made it back past Massa without too much difficulty. And everyone missed it but Webber is past Schumacher somehow. Hamilton has made a gap of four and a half seconds over Vettel. Wow.

Lap 8 Massa is off at Turn Three. White line. He nudges the barrier and breaks his rear wing, but manages to continue. He is now down in ninth. Meanwhile Alonso is on the gearbox of Rosberg.

Lap 9 And Alonso breaks sooooo late into Turn One but takes Rosberg, as he had intended. Perez is down in 19th for some reason. He presumably knows why.

Lap 10 5.3 seconds separate Hamilton and Vettel, who has been told he can pit when he wants. Massa has also been told he can pit when he wants to, “to provide some very useful information for Alonso,” says a cynical Brundle on the Beeb.

Lap 11 Red Bull are in the pits for Mark Webber, who pits. He is the first man onto slicks. Massa and a Toro Rosso are also in. Webber is slippy sliding all over the place. “One lap too early?” asks David Coulthard.

Lap 12 Button is in for slicks. He too slides around on the exit.

Lap 13 Race leader and second placed man Hamilton and Vettel are in! Alonso goes in too. Hamilton emerges just in front of Schumacher, who is immeditely past him because he is on inters in the damper first turn.

The second and third sectors are bone dry now.

Lap 14 Vettel and Button are in close attendance! Jenson Button passes him for second! Much more grip in the McLaren. And Webber is also flying and overtakes Alonso for fourth!

Lap 15 And Vettel has just been told not to hit the brakes and throttle at the same time. His team mate Webber runs wide at the first turn but Alonso is unable to capitalise.

Lap 16 Maldonado has a drive through penalty for speeding in the pit lane.

Lap 17 Hamilton sets the fastest lap, a 1m28.8. Quick. Vettel has not given up on second and may be soon on Button. Button is actually faster than Hamilton through the first sector, though.

Lap 18 Alonso and Webber are the fastest two on the track, battling as they are for fourth.

Lap 19 McLaren are saying that there is more rain on the way.

Heidfeld goes to overtake Kovalainen and cannot stop himself for love nor money. He loses two more places as he recovers. This means he is now 18th. Oh dear.

Lap 20 Rain in ten minutes, the forecast says. Trulli is out of the race, despite having impressed this weekend with his relative pace. An oil leak, they say.

Lap 21 Massa is challenging Schumacher for eighth but the Merc is lightning in a straight line. The order is now Hamilton, Button, Vettel, Webber, Alonso, Rosberg, di Resta, Schumacher, Massa, Kobayashi.

Lap 22 Massa is really losing time behind Schumacher. He is unable to pass his ex-team mate. Hamilton leads by 8.5 seconds.

Lap 23 Maldonado loses out to Sutil for 16th.

Lap 24 Massa level with Schumacher but has to lift. Meanwhile, McLaren tell Hamilton to cool his tyres. He is losing time to Button, by about 1.5 seconds this lap.

Lap 25 Heidfeld is on fire! He has hopped out, sharpish, as you might. And now it has exploded. How extraodinary. No one hurt, thankfully. Yellow flags.

Lap 26 The drivers are now pitting, emerging past Heidfeld’s stricken wreck. Hamilton now in at the end of this lap.

Lap 27 Heidfeld’s car was looking decidedly ill as it came out of the pits. Quite spectacular. Button in now from second.

Lap 28 As Button came out he came quite close to Perez, who was overtaking another competitor. Under yellow flags and surely illegally.

Lap 29 Schumacher retires and Vettel pits. He has come out ahead of Webber but not by much. They are fifteen seconds behind the leader Hamilton.

Lap 30 Massa gets past Rosberg as the German makes a mistake at turn four. That was for a net sixth, a place currently occupied by Kobayashi who is yet to pit for the second time.

Lap 31 The gap between Hamilton and Button is now settled around seven seconds. Perez is being investigated, presumably for that pass under the yellows.

That rain hasn’t materialised but it may yet do.

Lap 32 Alonso is on the back of Webber. That’s for fourth. The order is Hamilton, Button, Vettel, Webber, Alonso, Kobayashi, Massa, Rosberg, di Resta, Barrichello, Alguersuari, Petrivm Buemi, Sutil, Perez, Maldonado, Kovalainen, Glock.

Lap 33 Webber and Alonso close now! No cigar for the Spaniard.

Lap 34 Massa through past Kobayashi for sixth. Rosberg bearing down on the Japanese into the bargain.

Lap 35 Kobayashi pits as if to yield to the prevailing consensus that to stop again is a good idea. Not a lot else happening. Nick Heidfeld on his spicy event: “Something overheated…I was a bit scared. I felt some heat so I had to get out quickly. There was a small explosion…I have never seen anything like it before.”

Lap 36 Nada to report there, boys and girls.

Lap 37 Alonso pits. They are trying this ‘undercut’ thing. Bit of clear air for Alonso. Hamilton is told that his boots have to last for another nine laps.

Lap 38 Alguersuari gets Barrichello for ninth. Textbook.

Lap 39 Alonso is jolly nippy on these new tyres. Is it the best strategy? Only time will tell. He’ll have his work cut out trying to overhaul the McLarens. But he is trying damned hard.

Lap 40 McLaren are waiting til the cliff for Hamilton. Webber is in. Prime, not option. It may be better that way…

Lap 41 Well Hamilton is in now, so that was the “lower-risk” strategy according to Ted Kravitz. The Englishman was a bit slow away from his box…Vettel is slow on track meanwhile and has absolutely no grip. He will have to pit.

Lap 42 Button is staying out this lap and is the de facto leader. Vettel does pit, though. Alonso could have him…and he does. The Spaniard is ahead of the German. Good for him and for the team, that early pitting seems to have been successful.

Lap 43 And Button pits. He emerges JUST ahead of Alonso who is still travelling at quite a rate of knots. Looks as though Button can get up to speed early enough to keep the maestro behind him.

Lap 44 This is a real game of chess. Who has got this right? Hamilton is on the super soft and has to make that tyre last or pull out a gap and pit again. It doesn’t look good for him. Button is in the best seat in the house as he won’t need to stop again.

Lap 45 Schumacher had a gearbox failure. Vettel gets past Alonso for third in a great move down at the first corner.

Lap 46 Button gets told to look after his front left. He is catching Hamilton as the leader seeks to save his tyres.

Lap 47 And it is raining!! And Button has zoomed up to Hamilton and passed him! Button leads! Actually it is raining only on one corner! Hamilton spun, that’s why.

Lap 48 In trying to recover from that spin, Hamilton dropped the clutch and nearly collected Paul di Resta. He may have to suffer the consequences of that.

Lap 49 Hamilton was just the first person to arrive at the rainy bit. Red Bull’s radar says that it is raining.

Lap 50 Vettel is third and looking menacing to the two McLarens. The yellow harder rubber, which Button is on, will probably suffer more in these conditions which are now getting damper. But most of the track is dry!

Lap 51 Hamilton is very close to Button and challenging him for the lead. Hamilton is through! Button off at Turn two! Vettel is struggling in the changing conditions.

Lap 52 Button gets past Hamilton for the lead! But it only lasts one corner! Hamilton gets back past! Webber has pitted for inters…

Lap 53 And Hamilton is in for…intermediate tyres! This is only good if it continues to rain. And d’Ambrosio stacks it, rather hairily, in the pits, but mercifully hits no one and nothing. How quick is the inter relative to the slick? But it all may be immaterial as Hamilton is under investigation.

Lap 54 Webber, who was on dries, has now pitted for dries again. The inter is the wrong tyre as it has stopped raining. Alonso is past Hamilton.

Lap 55 And the stewards have handed Hamilton a drive-through for that burnout. “Double bad news,” says Brundle. He has to pit for dry tyres again to boot.

Hamilton pits for dry tyres.

Lap 56 After all that, Button leads, Vettel second, Alonso third, Hamilton fourth at the moment but has his penalty to take yet, Felipe Massa fifth, Webber sixth.

Lap 57 Vettel wants to win this. He has Button in his sights. Hamilton does his drive through and emerges behind Mark Webber, who is in fifth.

Lap 58 Button’s lead is five seconds over Vettel, but now a whopping 55 seconds over Hamilton in sixth. The Stevenage man will be gutted that a race he was leading has turned on him.

Massa is passed by Webber. And now Hamilton is threatening Massa! And he is through for fifth.

Lap 59 Button has responded to Vettel’s threat. Alonso spins but hasn’t lost any places.

Lap 60 Hamilton suffered from ‘first car fall’ there which allowed him to call for intermediates. Button scooped up the consequences. We have lost Kovalainen.

Lap 61 There’s a massive scrap going on for seventh involving di Resta, Kobayashi, Buemi, LAguersuari, Rosberg and Petrov.

Lap 62 And Kobayashi hit Alguersuari as Buemi went past and the Catalan tried to capitalise on his team mate’s move. He plummets to the back of that group.

Lap 63 And the Japanese has now gone to the back, and is now passed successfully by Alguersuari.

Lap 64 Webber and Hamilton arrive at that battle! And Hamilton is through past the Australian in the traffic. Can he get him back on the straight? No he can’t.

Lap 65 David Coulthard believes Kamui Kobayashi hindered Mark Webber there. Most sensible people do not agree. Kobayashi, for all his talents, is not capable of instant disappearance.

Lap 66 The order is Button, Vettel, Alonso, Hamilton, Webber, Massa, di Resta, Buemi, Rosberg, Alguersuari, Kobayashi, Petrov, Barrichello, Sutil, Maldonado, Perez.

Lap 67 Will Webber be able to challenge Hamilton back for fourth? Maybe.

Lap 68 Button has driven superbly in these conditions. He is excellent when the track is damp or drying. Fortune favours the brave and he has profited well from the situation, most particularly Hamilton’s strategic and physical errors and a bit of bad luck too.

Lap 69 Hamilton and Webber are approaching traffic, but it is unlikely they will come into play before the end of the race.

JENSON BUTTON WINS THE HUNGARIAN GRAND PRIX

A fantastic race from the Frome man! He is followed home by championship leader Sebastian Vettel, with Fernando Alonso the third man on the podium.

Fourth does go to Lewis Hamilton, with Webber fifth. Massa is sixth, di Resta seventh, followed by Buemi, Rosberg and Alguersuari.

Another instalment of excellent entertainment from the F1 crowd as they head into the summer break. Vettel knows that he can sleep comfortably as long as he can be there or thereabouts in the remainder of the season.

That’s all from me, thanks for following.