Klaus Graf and Greg Pickett gave the CytoSport Porsche team its maiden American Le Mans Series victory in a dramatic finale at Lime Rock.
Having come under heavy pressure from David Brabham's Highcroft HPD with just 10 minutes of the race remaining, the cars came together while lapping Luke Hines' GTC Porsche, Brabham's car being pushed onto the grass.
Graf was served with a stop/go penalty for causing the incident - which he took at the earliest opportunity - while Brabham sustained a rear puncture as a result of running off the road and was forced to pit for a replacement.
The result was that Graf, who had taken the car over from Pickett within the first hour, was able to ease off his pace on a track that had become slippery after rain began to fall during the final half hour. Brabham brought the car he shared with Simon Pagenaud home in second and maintained the pair's series lead in the LMP class.
Theirs were the only LMP cars in contention for victory as the Dyson Lola of Chris Dyson and Jonathan Cocker's Drayson Lola - both of which disputed the lead on the opening lap - hit problems early on.
The Drayson car did make the finish in 24th place, but was thwarted by suspected ECU problems that required a lengthy couple of pitstops.
Gunnar Jeannette and Elton Julian won the LMPC class in their Green Earth Team Gunnar machine.
Jeannette ran out of fuel on the last lap, but with the second-placed car of long-time leaders Alex Figge/Tom Papadopoulos having been lapped for a final time by Graf with just 100m to go before the finish line, Jeannette hung on to victory.
Pat Long and Jorg Bergmeister collected the Flying Lizard Porsche team's third GT win of the year, the crew taking the chequered flag by just 1.5s from the Bill Auberlen/Tom Milner BMW.
Long/Bergmeister claimed the championship lead from Risi Ferrari crew Jaime Melo/Gianmaria Bruni. Melo was put into the tyres early on by Johnny O'Connell's Corvette, which later retired.
Victory in the GTC class went to TRG and drivers Andy Lally and Henri Richard, who came out on top in a battle with the Jeroen Bleekemolen/Tim Pappas Black Swan Porsche.
Pos Cl Drivers Car Time/Gap 1. P Pickett/Graf Porsche 2h45m04.386s 2. P Brabham/Pagenaud HPD + 27.810s 3. PC Jeannette/Julian ORECA + 9 laps 4. PC Figge/Papadopoulos ORECA + 9 laps 5. GT Bergmeister/Long Porsche + 10 laps 6. GT Auberlen/Milner BMW + 10 laps 7. GT Muller/Hand BMW + 10 laps 8. GT Salo/Kaffer Ferrari + 11 laps 9. GT Beretta/Gavin Corvette + 12 laps 10. PC Tucker/Wallace ORECA + 13 laps 11. GT Sharp/van Overbeek Ferrari + 14 laps 12. GT Law/Neiman Porsche + 14 laps 13. GT Sellers/Henzler Porsche + 15 laps 14. GTC Richard/Lally Porsche + 19 laps 15. GT Dalziel/Goossens Jaguar + 19 laps 16. GTC Pappas/Bleekemolen Porsche + 20 laps 17. GT Brown/Cosmo Ferrari + 21 laps 18. GTC Lewis/Vento Porsche + 22 laps 19. PC Sedivy/Zugel ORECA + 25 laps 20. GTC Curtis/Sofronas Porsche + 25 laps 21. GTC Miller/Hines Porsche + 31 laps 22. P Field/Field Lola + 31 laps 23. GTC Sweedler/Kapudija Porsche + 48 laps 24. P Drayson/Cocker Lola + 58 laps 25. GT Murry/Robertson Doran + 61 laps Retirements: PC Marcelli/Wong ORECA 108 laps GT Magnussen/O'Connell Corvette 35 laps GT Melo/Bruni Ferrari 22 laps P Dyson/Smith Lola-Mazda 7 laps PC Tucker/Bouchut ORECA 0 laps