WEC: LIVE updates from WEC at Circuit of The Americas

Polesitter Sebastien Buemi retains his advantage at the start of the race, heading Romain Dumas's Porsche and immediately pulls out a gap of 10sec. But Dumas is under investigation for his start.

The second Toyota of Alex Wurz runs third ahead of Mark Webber's Porsche with Andre Lotterer and Loic Duval fifth and sixth in the Audis.

• Dumas is cleared of transgression, but he loses second to Wurz, so we now have two Toyotas followed by two Porsches and two Audis.

• After 17mins, Lotterer ruins the symmetry by slotting the No. 2 Audi past Webber and into fourth. Now, Duval is all over the No. 20 Porsche.

• With 30mins gone, in P2, the ORECA-Nissan of Richard Bradley leads the class with Ryan Dalziel in the Extreme Speed HPD second, chased by the Ligier of Olivier Pla.

• Lotterer dives past Dumas to grab third. Now, what can he do about hunting down the Toyotas? Buemi's lead is 25sec over Wurz after 34mins.

• Dalziel is into the lead of P2 following a spin for polesitter Bradley.

• 42mins in, Stefan Mucke's Aston Martin leads Gimmi Bruni's Ferrari and Nick Tandy's Porsche in GTE Pro, while Richie Stanaway, is top of the GT-Am pile in another Aston Martin.

• Sebastien Buemi spins away much of his lead with an incident at Turn 13 on his 24th lap. However, he retains his place in P1...and carries on setting faster times than teammate Wurz!

• Duval demotes Dumas to fifth, so it's now two Toyotas, two Audis, two Porsches.

• Scott Sharp has taken over from Dalziel in the ESM HPD, while Pla has taken the lead, with Bradley second and Sharp third.

• No. 1 Audi makes its first pit stop after 50mins.

• Five hours to go. The leader stops and hands over to Nicolas Lapierre. Meanwhile the second Toyota, the No. 7, is now in the hands of IndyCar race winner Mike Conway, Neel Jani has replaced Romain Dumas in Porsche No. 14 and Webber hands off No. 20 Porsche to Timo Bernhard.

• Frederic Makowiecki leads the GTE Pro cars into the pits.

• After 1h10mins, the order is Lapierre, Lotterer, Duval, Conway, Jani, Bernhard, Kraihamer, Prost as the top 8, the latter two in Rebellions.

• In P2, Olivier Pla leads Richard Bradley and Scott Sharp.

• In GTE Pro, Toni Vilander's Ferrari heads Darren Turner's Aston Martin, Jorg Bergmeisters' Porsche and Patrick Pilet's Porsche.

• P2 in P2 changes hands as Mr Scott Sharp dives past Bradley into Turn 1. That then becomes the lead as Pla hits pit road, having handed off to Roman Rusinov.

• 4hr30min into the race...and the rain hits hard at Turn 11.

• Now it's falling hard everywhere and a festival of spinning begins - including the leading Toyota and the No. 7 Toyota (ABOVE) – Pic, Loran Hygema.

To be honest, this is turning ridiculous. The Porsches are apparently beached.

Andre Lotterer kept his head and took the lead and handed over to Benoit Treluyer.

And now there's a RED FLAG.

The survivors are assembling on the grid (BELOW, Pic - Marshall Pruett) . Meanwhile flatbeds and cranes are about to start trying to remove cars from gravel traps.

• Both Audis survived the rain-induced farce with Benoit Treluyer keeping the No. 2 car on the island, and Tom Kristensen now in second with Audi No. 1

Mike Conway has the No. 7 Toyota up into third, and we saw Lapierre made it back to the pits in the No. 8 car.

Timo Bernhard is driving cautiously back to the pits in the No.20 Porsche.

• If you're an American or a Scot or just a fan of Tequila Patron, three cheers for Scott Sharp and Ryan Dalziel who currently run third in P2.

• Darren Turner's Aston Martin heads Toni Vilander's Ferrari and Jorg Bergmeister's Porsche in GTE Pro.

• In GTE Am, David Heinemeier-Hansson's Aston Martin is top dog, ahead of teammate Paul Dalla-Lana.

So that's up to date for now...

GREEN FLAG with 3hr19min left of the race

• Everyone behaving themselves on the restart. Lapierre passes Kristensen but he is a lap down, so it's currently Treluyer leading TK in an Audi 1-2, with Neel Jani third in Porsche No. 14, Lapierre fourth in the Toyota No. 8, Bernhard in fifth in the second Porsche and Nick Heidfeld sixth in the Rebellion and Conway 7th in the No. 7 Toyota.

• SMP Racing's ORECA-Nissans run 1-2 in P2 ahead of Sharp's ESM Racing entry.

• 3h11m to go - Patrick Pilet grabs third in GTE Pro from Vilander's Ferrari to complete a Porsche 2-3 behind Turner's Aston Martin.

• Khaled Al-Qubaisi is leading GTE Am in the Proton Porsche ahead of Francois Perrodo in the Prospeed Porsche.

• No. 20 Porsche, currently a lap down in fifth, pits after 59 laps and receives new front bodywork.

• Toyota No. 8 pits, as does leader, the No. 2 Audi.

• Neel Jani's Porsche is now right up on the tail of Kristensen and this is now a duel for the lead, following Treluyer's stop.

• Perrodo's GTE Am Porsche running very slowly off-line.

• Jani puts Porsche into the lead on lap 65,  and he's rapidly pulling away from the nine-time Le Mans winner. It's a three-second lead after just one lap.

• 2h55 to go and Jani is rocketing away from the field. Pulls another 4sec out next time through.

• Patrick Pilet has overtaken his teammate Bergmeister and is now only 1.9sec behind Turner's Aston Martin. Battle to be joined shortly, it seems.

• Well that didn't take long. Pilet is into the lead of GTE Pro, having taken some very interesting lines trying to find grip and avoid Turner's spray.

 • With 2h39min to go, Lapierre's No. 8 Toyota (ABOVE, Pic. Marshall Pruett) slips easily past his teammate Conway into fourth. Almost simultaneously, Kristensen pits from second place, handing the spot to Audi teammate Treluyer's No. 2 car who is now carving into the sub-2min category, like Lapierre. Treluyer is 33sec behind leader Jani.

• While this was going on, Bernhard finally moved the No. 20 Porsche past the No. 12 Rebellion car of Heidfeld to take sixth place.

• Mike Conway has pitted No. 7 Toyota after 74 laps and handed over to Stephane Sarrazin.

• Treluyer is making no inroads into Jani's 30sec-plus advantage at the front.

• Frederic Makowiecki and Nick Tandy have taken over the Team Manthey Porsches leading GTE Pro, from their respective co-drivers Pilet and Bergmeister. The lead Porsche (Makowiecki) has a 4sec lead over its stablemate, with Stefan Mucke's Aston Martin now 22sec behind.

• 2h21m to go - Jani pits the lead Porsche 919 HYBRID which allows Treluyer's Audi into the lead. It will be interesting to monitor how quickly the Swiss star can reel in the Audi R18 e-tron quattro.

• The No. 37 SMP Racing ORECA-Nissan has been pulled into the garage for a long stop.

• We don't want to get overexcited about our friends at Extreme Speed, but Ryan Dalziel is in the middle of a remarkable performance. He's been setting 1min59sec laps – some 5sec quicker than the three cars ahead of him in P2.

• Regarding the lead battle, Jani, with 2h05m to go, is only matching, not catching Treluyer. They remain around 25sec apart. However, now it's Treluyer's turn to pit and he hands the No. 2 Audi over to Marcel Fassler.

• 2 hours to go - Jani's Porsche leads Kristensen's Audi by 53sec and Fassler's Audi by 60sec. Anthony Davidson is fourth, a lap down in the Toyota TS 040 Hybrid, but a lap ahead of Brendon Hartley in the second Porsche.

• Rebellion Racing No. 13 has been dragged into the garage.

• 1h50m to go, and Fassler his hassling Kristensen for second … and he's got it on the 98th lap. He's 53sec behind Jani's Porsche. Again, let's see what Fassler can do, if anything, about that 919 HYBRID.

• Sorry, the battle of the Prototypes has been a bit distracting, as have the fireworks (literally) up at Turn 1. But let's not neglect GTE Pro where the Porsches of Makowiecki and Tandy remain just 1sec apart with Mucke's Aston Martin a further 20sec down. In fourth and fifth are the two AF Corse Ferraris.

• Meanwhile in GTE Am, with 1h41m to go, the No. 88 Proton Porsche of Christian Ried (currently driving), Klaus Bachler and Khaled Al-Qubaisi is leading by 80sec from the two Aston Martin Racing Vantage GTEs.

• Neel Jani pits the No. 14 Porsche and hands over to Marc Lieb and Kristensen hands the No. 1 Audi to Lucas Di Grassi, that guy who won the inaugural Formula E race ;-)

• We were about to declare either Anthony Davidson or Ryan Dalziel as our unofficial Beast Of The Hour, but di Grassi just set the No. 1 Audi's quickest lap of the race, ducking straight into the 1min51secs. Lieb has done the same as he attempts to close the 35sec gap to Fassler in the No. 2 Audi.

• 1h23m to go - Extreme Speed Motorsports is leading P2 by half a minute and has made the same number of pit stops as its rivals. Tsugio Matsuda in third for KCMG, which suffered a long stop in its ORECA-Nissan, is doing a great job matching Dalziel's times, but from 1min40sec behind.

• Nick Tandy has his second mechanical disaster in as many races when he has engine difficulties and it takes forever to restart after a pit stop. He's now a lap down on teammate who has Darren Turner's Aston Martin less than five seconds behind him.

• Finally Davidson pits the No. 8 Toyota from third place and hands over to Sebastien Buemi.

• 1h06m to go - Marc Lieb is back in front for Porsche as Marcel Fassler has pitted the lead Audi. A lap later, Brendon Hartley pits the No. 20 Porsche.

• Fassler is only 1.1 sec behind Lieb in the Porsche following the No. 2 Audi's pit stop…, with 62minutes to go.

• Maurizio Mediani has moved to the front of P2 for SMP Racing, and Matsuda has taken second for KCMG, as Ed Brown plays hismelf in carefully in the Extreme Speed HPD.

• GTE Pro is looking predictably interesting, as Darren Turner is just 1.3sec off Pilet's Porsche.

• No. 14 Porsche (ABOVE, pic. Marshall Pruett) of Lieb has a lead of 2.239sec over Fassler with 50mins to go.

• Di Grassi pits No. 1 Audi for fuel and tires

• Turner takes the lead from Pilet on their 118th lap, with a move that started in Turn 1 but only finished in Turn 3. Damn, Circuit of The Americas layout is great for allowing so much side-by-side action.

• Lieb pits with 43mins to go, allowing Fassler back in front. It's a quick stop but he rejoins some 55sec behind.

• Half an hour to go, and Sebastien Buemi just set the No. 8 Toyota's fastest time of the day with a 1min50.390sec lap. He's third, hurtling along 20sec in arrears of Lieb's Porsche. Mind you, he has to get on with it for another reason - the No. 1 Audi of Di Grassi only nine seconds behind him.

• 28 mins to go and Hartley brings Porsche No. 20 into the pits and hands over to Mark Webber.

• Buemi slashes by into second as Lieb does a 1min58sec lap after getting badly baulked by a backmarker. Buemi is setting some sensational lap times, sometimes as much as three seconds quicker than the leader, but he's 73sec in arrears… and he's got to stop again.

• Lucas di Grassi is into third ahead of Lieb…which becomes second as Buemi pits and drops to fourth, behind the Porsche once more. This final quarter-hour should be a treat if you're a Toyota fan though. Buemi is crazy-quick around here.

• Buemi is up into third after an around the outside maneuver on Lieb at Turn 19…on his out lap!

• Fassler pulls No. 2 Audi from the lead onto pit lane. He resumes in the lead, still 90sec clear of teammate di Grassi who is 12sec ahead of Buemi's Toyota. Do not discount the Swiss's chances of splitting the Audis by the time they reach the checkers.

• Scratch that. Di Grassi is actually going quicker. The Audis are well on their way to a 1-2 finish here at Circuit of The Americas.

• Nicolas Minassian has put up a strong fight for SMP Racing, but P2 class honors will fall to the KCMG lineup of Richard Bradley, Tsugio Matsuda, and Matthew Howson.

• Darren Turner/Stefan Mucke takes GTE Pro honors ahead of Patrick Pilet and Frederic Makowiecki's Porsche 911 and Gimmi Bruni/Toni Vilander in the AF Corse Ferrari 458 Italia.

• GTE Am 1-2 goes to Aston Martin Racing, with Pedro Lamy sending the No. 98 across the line just one second ahead of the No. 95.

And that's a wrap from a warm Circuit of The Americas and a cold media center. Thanks for sticking around folks. Report to follow.