Frank Biela, Marco Werner and Emanuele Pirro celebrate their win at Sebring.

Another win for Audi, the first for Acura and Andretti Green Racing, and the most exciting finish in race history marked the start of the 2007 American Le Mans Series on Saturday. Marco Werner, Emanuele Pirro and Frank Biela drove to victory at the 55th Mobil 1 Twelve Hours of Sebring in one of the most thrilling editions of the Florida classic in its history.

It marked the second straight Sebring win and ninth victory in as many races in the short life of the diesel-powered Audi R10 TDI. Werner crossed the finish line after 363 laps for his third victory in five Sebring starts. Biela won for the fourth time in America's greatest sports car race (tied with Tom Kristensen), and Pirro won for the first time since 2000.

Werner was seven laps up on Bryan Herta in the Andretti Green Racing Acura ARX LMP2 entry that he shared with Dario Franchitti and Tony Kanaan. The Audi trio came back from a punctured tire, pit lane penalties and a two-lap deficit to win.

"I would have never put money on our car," Pirro said. "When you are two laps behind, it's very tough. I just had to put my foot down and race. We had to believe we were still tough competitors. Today's race was very demanding, and every car had problems with mechanicals. We never had a mechanical (issue) and that is another reason why I am so proud to be an Audi R10 TDI driver."

Werner started on pole position and ran with its sister car of Allan McNish, Rinaldo Capello and Tom Kristensen. That trio led most of the opening five hours after the winning car had its problems. After the five-hour mark, McNish pitted and handed off to Capello, who couldn't get the car rolling. The team replaced a battery, starter motor and electrical dashboard before rejoining the race after a 30-minute stop.

"It was a tough race, the TDI was running good but you never know what will happen," Werner said. "So you have to push all day long and you never feel safe."

The class win for Andretti Green Racing came less than a year after Acura publicly announced its entry into the American Le Mans Series. Herta, Franchitti and Kanaan led overall three different times and finished two laps ahead of the Lowe's Fernandez Racing Lola of Adrian Fernandez, Luis Diaz and David Martinez.

Andretti Green Racing gave Acura an LMP2 class win in the Series debut for both.

It is quite an accomplishment for an Acura program that hit the track for the first time in late August. But miles and miles of testing, a 12-hour simulation race at Sebring and many months of tireless work paid off.

"I can't put it in words. I would rate it as one of the highest emotional experiences I've had," said Robert Clarke, president of Honda Performance Development. "So much work went into this program. It has been a long road, not just for HPD but for Acura, our teams, sponsors, drivers, everyone who is involved in the program. I couldn't have been so bold as to dream of this result."

The three Acura entries (Highcroft Racing was fourth in class) mostly ran steady throughout the day. Aside from electrical issues with the Highcroft prototype, the Acuras were immune from major problems up until the final hour. The Andretti Green entry made two unscheduled stops in the last 35 minutes to add gear oil as Herta had trouble shifting in the closing moments.

"I really couldn't catalog all the problems from the last hour," Herta said. "Right from the beginning we were having battery voltage problems so we couldn't use a lot of the electronics. Then we had problems with the gearbox and gave us troubles. I think in the last 10 laps the car shut off half a dozen times and re-fired.

"I have to take my hat off to the group," he added. "I have never seen a group that has worked so hard and put in so much effort. You wouldn't believe how many problems we had in testing and it's a testament to bring it here and to bring us this result."

Porsche's four RS Spyders found significantly more trouble. Electrical problems and other maladies set entries from Penske Motorsports and Dyson Racing back in the race's first half. Penske's Romain Dumas, Timo Bernhard and Helio Castroneves weathered the storm well enough for a third-place finish in class.

In GT1, Corvette Racing won its class for the fifth time in six years as Oliver Gavin, Olivier Beretta and Max Papis took a 17-second victory over their sister car in a race that saw the two Corvettes on the same lap the entire way. Beretta and Gavin won last year with Jan Magnussen, who teamed this year with Ron Fellows and Johnny O'Connell.

"Like everyone knows, Sebring is a tough track and is a great test for Le Mans," said Beretta, the Series' all-time leader with 29 wins and a three-time winner at Sebring. We worked very well and had fantastic pit stops as usual. The car at the end of the race was like it was on Lap 1. This team knows exactly what to do. We pushed the car because we had strong competition with the No. 3 car. Everything went perfectly."

Saturday also marked the first race for a new production-based air conditioning unit in the Corvette C6.Rs. Like the car and team, the AC unit received a workout Saturday in preparation for Le Mans and came away a winner. Corvette Racing will use the unit at the 24 Hours of Le Mans in June and for the full American Le Mans Series season.

"This was a fantastic test for us," said Gavin, now a four-time Sebring winner. "The AC performed so well that we sometimes wanted to turn it off, and that's unusual for a closed car. Nearly every driver who got out of the car was looking fresh and really good. If we can stay focused and sharp and fresh, that will be a really big, big help at Le Mans."

The race marked the last at Sebring for Corvette Racing pioneer Fellows. He, Magnussen and O'Connell competed in a special Arctic White C6.R as a tribute to Fellows. The two Corvettes finished comfortably ahead of Team Modena's Aston Martin DBR9.

Undoubtedly the highlight of the day was the GT2 class finish. Risi Competizione's Jaime Melo beat Jorg Bergmeister of Flying Lizard Motorsports to the finish line by 0.20 seconds, the closest finish in Sebring's 55-year history and the closest finish ever in the American Le Mans Series' GT2 class.

Melo, who drove with Mika Salo and Johnny Mowlem, led by five seconds with 11 minutes left but by the final lap Bergmeister was tucked right behind his rear bumper. The two cars crossed the start-finish line just before Werner took the checkered flag. So instead of a one-second victory, Melo had to hold off the young Porsche factory driver for another full circuit.

Bergmeister, partnering with Johannes van Overbeek and Marc Lieb, finally caught up with Melo entering Turn 16 and on to the long backstretch. He pulled alongside Melo and barely moved past him as the two headed into the final turn. They remained door-to-door and made contact as Melo edged across the line.

"It was a fantastic last lap," Melo said. "I've never had a finish like that. I had brake problems late and tried to keep it steady. He (Bergmeister) overtook me on the backstraight and I braked a little early. Out of Turn 17 I put in a little more and opened the throttle as soon as possible."

The battle between the Ferrari and Porsche lasted throughout the entire day. The Ferrari survived start from the rear of the grid, a late drama in pit lane with a 20-second penalty and a Turn 17 spin at sunset for the team's fifth win in the last seven events dating back to July of 2006 at Salt Lake City. Tafel Racing's Porsche of Wolf Henzler, Robin Liddell and Patrick Long finished third.

"It was really tight with the No. 45 car," Salo said. "We were absolutely flat out the entire way. The GT2 is the best racing in this Series. It's going to be like this all year, so we have to improve so we don't have any more finishes like this."

"It was just awesome," Mowlem said. "Every time we were out there, we were driving as hard as we could. To finally get to the end and have Jaime drive for two hours like he did and have that kind of final lap, he's my hero. To win is just fantastic."

The next round of the American Le Mans Series is the Acura Sports Car Challenge of St. Petersburg. The race will start at 5:05 p.m. ET on Saturday, March 31. SPEED will provide a same-day broadcast event from 8:30 to 10 p.m. American Le Mans Radio and IMSA's Live Timing & Scoring will be available at americanlemans.com.