PK Saleen duo Bert Longin and Anthony Kumpen ended a miserable season on a high by taking a shock win in the dramatic FIA GT Championship finale in Argentina, as Michael Bartels and Andrea Bertolini clinched the drivers' title in fifth place.
Fabrizio Gollin and Mike Hezemans (Phoenix Corvette) finished a close second, but their title hopes depended on Vitaphone Maserati duo Bartels and Bertolini finishing outside the top six.
In the event their conservative fifth made Bartels and Bertolini champions for a second time, and gave the team their third straight drivers' crown.
Marcel Fassler and Ricardo Risatti had looked set to take a dominant win for Phoenix at the breathtaking new San Luis track, only for Fassler to crash out of the lead with just 22 minutes remaining - having controlled most of the race.
Pole-winner Fassler was beaten away by Larbre Saleen's Frederic Makowiecki at the start, with the Frenchman - in only his second FIA GT1 appearance and his first since Dubai 2006 - fending off Fassler's pressure over the opening laps before briefly pulling out a three-second lead.
But as the first stops approached, the Corvette calmly closed back onto the Saleen's tail, with Fassler slicing ahead on lap 18.
Mackowiecki stayed in touch, only for his co-driver Roland Berville to end Larbre's hopes of victory when he hit the wall on the first lap of his stint.
That left Fassler and Risatti with an enormous lead over their teammates Gollin and Hezemans, who had moved up from an early sixth place thanks to good pit work and other teams' problems.
They lost second to Kumpen's PK Saleen just before the final stops, but Hezemans was able to re-pass Kumpen's co-driver Longin early in the final stint.
That pass turned out to be for the race lead, as at the same moment Fassler ran wide at the final corner and clouted the wall, costing him and Risatti a comfortable win.
Hezemans therefore picked up the lead, but could not shake off Longin, who slipped back ahead with eight minutes to go and subsequently resisted huge pressure from the Dutchman to claim the victory.
The race then came to a bizarre end when the two leaders tangled amid traffic on the slowing down lap, with the victorious PK Saleen sustaining broken suspension and spinning into the wall. The stewards are investigating both drivers' actions.
With the second Vitaphone Maserati retiring after Alexandre Negrao hit the wall avoiding a GT2 car, Maxime Soulet and Christian Ledesma came through from the back of the grid - having lost their qualifying times due to a tyre infringement - to complete the podium for SRT Corvette.
Fellow back row starters Jose Maria Lopez and Esteban Tuero took fourth. Lopez tore through the field in the ageing ACA Argentina Ferrari in the first stint, getting as high as third before losing time with a slow pit stop.
Local duo Matias Russo and Luis Perez Companc (Advanced Engineering Ferrari) took a popular home win in GT2, but only after the AF Corse Ferrari slowed dramatically in the flying laps.
Until then, GT2 champions Gianmaria Bruni and Toni Vilander had appeared to be on course to take class victory from the back of the grid following Vilander's qualifying crash. Pole-sitter Russo had pulled away early on, but his co-driver Companc lost the lead to the flying Vilander just before half-distance, only for the AF Corse car's huge lead to disappear in the final moments, allowing Russo and Companc to take the win after all.
Christian Montanari and Thomas Biagi completed the podium in the second AF Corse Ferrari, while Emmanuel Collard and Richard Westbrook's Prospeed Porsche was an early retirement.
Pos Cl Drivers Car Time
1. GT1 Longin/Kumpen Saleen S7 2:00:02.994
2. GT1 Hezemans/Gollin Corvette Z06 + 0.561
3. GT1 Soulet/Ledesma Corvette Z06 + 34.211
4. GT1 Lopez/Tuero Ferrari 550 Maranello + 1:42.310
5. GT1 Bertolini/Bartels Maserati MC 12 + 2:13.996
6. GT2 Russo/Perez Companc Ferrari F430 + 1 lap
7. GT2 Bruni/Vilander Ferrari F430 + 1 lap
8. GT2 Montanari/Biagi Ferrari F430 + 1 lap
9. GT2 Kirkaldy/Bell Ferrari F430 + 2 laps
10. GT2 Palttala/Forsten Porsche 911 GT3 RS (997) + 2 laps
11. GT2 Malucelli/Ruberti Ferrari F430 + 2 laps
12. GT2 Babini/Davies Ferrari F430 + 2 laps
13. GT2 Cadei/Moser Ferrari F430 + 2 laps
14. GT2 Mullen/Niarchos Ferrari F430 + 5 laps
15. GT2 Camathias/Balbiani Ferrari F430 + 6 laps
16. GT1 Fassler/Risatti Corvette Z06 + 10 laps
17. G2 Kuppens/Leinders Gillet Vertigo + 24 laps
18. GT1 Mackowiecki/Berville Saleen S7 + 26 laps
19. GT1 Negrao/Ramos Maserati MC 12 + 31 laps
20. GT1 Mazzacane/Basso Ferrari 550 Maranello + 34 laps
21. GT2 Collard/Westbrook Porsche 911 GT3 RS (997) + 46 laps