Emanuele Pirro withstood a furious charge from Lucas Luhr in the final 20 minutes as the Audi R10 TDI claimed victory its first American Le Mans Series race since March by winning the Utah Grand Prix on Saturday at Miller Motorsports Park.

Pirro and the diesel-powered Audi R10 TDI crossed the finish line 0.314 seconds ahead of Luhr's Penske Racing Porsche RS Spyder. The difference turned out to be a fuel-only change with just more than an hour left for the Audi. The Porsche took on fuel and tyres and changed drivers one minute later, hoping fresher tyres would allow Luhr to catch the Audi. In the end, it didn't.

"This was a great race," said an exhausted Pirro, who won with Frank Biela on Saturday and at the 24 Hours of Le Mans in June. "I thank God I have 27 years of experience because the last few laps were so difficult."

Biela began on pole position but went off track in Turn 3 of the first lap. He then also was involved in a final-turn incident with a slower GT2 car. Chances looked pretty bleak, but typical Audi pit strategy and the torque of the V12 diesel won out.

"The first thing I have to say is this guy won the race despite the other car having problems," Biela said of Pirro. "I was struggling at the beginning. I don't know why. The first turn maybe because there wasn't enough heat in the tyre. Our aim was to stay close as possible to the Dysons and our sister car, but unfortunately it was not like that. Then after the pit stop and this old fart got in, I was just giving him motivation. It shouldn't be so easy for him all the time."

The Dyson Racing Lola of James Weaver and Butch Leitzinger finished second in class, about a half minute in front of the other Audi R10 TDI of championship leader Allan McNish and Dindo Capello.

"The cars seem to be coming around a little bit," Dyson Racing owner Rob Dyson said. "We have been working on reliability. We have a lot of work to do, but I'm cautiously optimistic."

Penske Racing earned its third straight victory as Luhr and Sascha Maassen cruised after the sister car of Timo Bernhard and Romain Dumas stopped at the pit exit with throttle problems. The victory propelled the two Germans to within 1 point of the class championship lead, held by Intersport Racing's Clint Field and Liz Halliday, who finished second in class together in their Lola B05/40-AER.

"We were looking forward to our first win (of 2006)," Maassen said. "It took a little bit and now we're there."

Everyone associated with Penske and Porsche weren't disappointed the team didn't their second overall race of the season. The P2 class championship has been the goal from the beginning and will continue to be through the season finale. Still, the chance was there to pull off one of the biggest stunners in recent sports car racing history.

"We put on a good show. I really didn't have a chance to pass (Pirro) by myself," Luhr said. "Because the way the tyres were (double stinted), I think they had more troubles getting rid of the pickup than I did. You could see after the first laps after the safety lap I was closer because I could clean my tyres better. Once he got cleaner he pulled away."

Aston Martin Racing won for the second straight race in GT1 as Tomas Enge and Darren Turner won for the first time this year. Their Aston Martin DBR9 finished a lap ahead of their sister car, driven by Andrea Piccini and Stephane Sarrazin. The two Aston Martins also finished 1-2 in class for the first time since making their Series debut at Sebring last year.

The British marque's third win in North America wasn't without a little late drama, though. The team had planned to pit with about 15 minutes remaining while leading by nearly a full lap. Fortune smiled when Enge pitted under yellow for tyres and fuel, only for the crew to find that the battery was losing voltage and that they had to replace the alternator belt.

Quick work combined with the full course caution meant Enge retained his lead, which he held comfortably for the remainder.

"The change was pretty short," Enge said, bragging on his team. "We were already a lap ahead, and that was actually a scheduled pit stop. It took half a minute to repair that, and we didn't lose anything. We were cruising at the end."

Risi Competizione gave Ferrari its first victory in the Series since the 2004 season with a GT2 class victory. Jamie Melo and Mika Salo came from the back of the grid after changing tyres prior to the start for their first win in the Series and the first for the Ferrari F430GT. They also are the fifth pairing to win a Series race in as many events.

They finished 11 seconds ahead of the Petersen Motorsports/White Lightning Racing Porsche of Patrick Long and Jorg Bergmeister.

"I just tried to be safe in the first three or four laps," Melo said. "After that, I just pushed to get the lead. The car was working very well, and the tyres were good too. I overtook the leader just trying to keep the pace and conserving the tyres."

At each of the previous four events, the new Ferrari has posted the fastest class time in at least one session. That made Saturday's result feel a bit more rewarding for Salo and Melo.

"We've been leading every race so far and have had some problems," Salo said. "We had power steering at Houston and got taken out at Mid-Ohio. This is the first time we've finished the race. We still are a little slow in a straight line, but in the corners and in the turns, the car is unbelievable."

Johannes van Overbeek and Wolf Henzler finished third in the Porsche of Flying Lizard Motorsports. It allowed the team and van Overbeek to retain their season championship leads.

The next round of the American Le Mans Series is the Les Schwab Tyres Presents Portland Grand Prix on Saturday, July 22.