FONTANA, Calif. - After testing at California Speedway in January, Greg Biffle had a feeling he would win the Auto Club 500.

He did - barely.

Biffle, fighting a car that wanted to jump out front under him, somehow held on long enough to take the checkered flag Sunday in the second NASCAR Nextel Cup race of the season.

"I lost all the rear grip there with three (laps) to go," Biffle said as he celebrated his fourth career victory. "I just barely touched the wall, skinned it, two or three times there at the end and I was just able to keep it under me.

"We had the fastest car on the racetrack, but just not right there at the end."

Biffle, who won the last year's season finale in November, left the test on California's 2-mile oval with a lot of confidence.

"I had a pretty strong feeling that we would win out here," he said. "Ninety percent of the time in our sport the fastest car doesn't win the race. Today, I feel the fastest car won."

Biffle ran strong throughout the 250-lap race, taking the lead for good on lap 228 and building an advantage just big enough to hold off a last-ditch effort by runner-up Jimmie Johnson.

Johnson passed reigning Cup champion Kurt Busch on the last lap to take second and came up just 0.230 seconds - about six car-lengths - behind the winning Ford Taurus.

"If we just had another corner, I think there would have been a different outcome to this race," Johnson said. "Man, I saw Biffle hitting the wall and sideways a few times there at the end and I could hardly believe he got to the end. But he had a strong car and he did a really good job."

Biffle, who figured out the right combination in the first test of NASCAR's new aerodynamic rules, twice came back from as far down as 30th.

"I had to pass every car and I earned it," Biffle said. "That's why I freed the car up so much is because I was back in that traffic. Then, when I got back out front it was so dang loose that I couldn't drive it."

Roush Racing had a great day, with Biffle winning his fourth Cup race, reigning series champion Busch finishing third and taking the series lead by five points over Johnson, Carl Edwards fifth and Mark Martin seventh. Matt Kenseth also ran in the top 10 most of the day, but fell off the lead lap on lap 234 with a flat tire and wound up 26th.

The key moment came on lap 218 when Busch, running second, and Biffle, in fifth, stayed on track while leader Kevin Harvick and most of the other contenders pitted for tires during the last of seven caution periods.

Busch, faked toward the pits before driving back onto the track, taking the lead, with Biffle just behind. Biffle was able to drive into the top spot seven laps after the green flag waved for the final time.

"It wasn't a really hard decision," Biffle said about staying on track. "We only had seven laps on those tires. Those Goodyear tires they brought here are a really good compound and it takes five laps for them to come in, so we only had a two-lap advantage by pitting."

Johnson was one of several drivers who did pit for four new tires on the last stop and he fell to 10th on the restart.

"It worked for them because the four-tire guys got hung up in traffic," Johnson said. "We should have been able to win that race."

Busch, off to a strong start after finishing second to Jeff Gordon in the season-opening Daytona 500, was disappointed with Sunday's result.

"You get so close, you just want to be able to capitalize," he said. "I ran so hard at the beginning (of the last stint), I smoked my tires and Johnson got us there at the end."

Jamie McMurray finished fourth, followed by Edwards and Harvick.

This was the first race in which the Cup cars ran with shortened rear spoilers and softer tires, an effort by NASCAR to make the racing more competitive and allow more passing by taking away downforce and putting more responsibility in the hands of the drivers.

It also was the first time the teams had to start the race with NASCAR holding the cars from the end of qualifying Saturday until Sunday morning and allowing only minor adjustments before the start.

"What I did find kind of ironic today was that my car - I don't know about everybody else's car - was real bad behind other cars," Biffle said. "It's the same problems that we always have when you're behind another race car. I don't think we really got a true feeling for what the new package is going to be like. When we get to Texas or Atlanta, that's when you're going to see something."

Joe Nemechek appeared to have the strongest car for much of the race, leading a race-high 63 laps before his engine blew. Nemechek was one of five drivers using Hendrick Motorsports engines, including Gordon, who had problems during the race.

Gordon, the defending champion in this race and a three-time winner in California, was still in contention when he lost a cylinder late. He wound up 30th.

AP-ES-02-28-05 0328EST