BRISTOL, Tenn. — Matt Kenseth continued his momentum-building run toward the Chase for the championship Saturday night, pulling off a weekend sweep at Bristol Motor Speedway by winning the Sharpie 500.

His fourth win of the season clinched him a spot in NASCAR's 10-race playoff format, which begins Sept. 17 in New Hampshire.

It also showed he's peaking at the perfect time. Tony Stewart got hot midway through the summer last year and streaked to his second Nextel Cup title.

Now Kenseth, winner of three straight NASCAR races, hopes to do the same. He is the first driver since the late Dale Earnhardt in 1987-88 to win the Bristol night race in back-to-back seasons.

"The last two weeks have been just unbelievable," he said. "If we can go into the Chase like this, we'll have a shot at the championship."

Kenseth won last week's Cup event in Michigan, then Friday night's Busch Series race at Bristol. He needed a gutsy pass of Kevin Harvick to get the Busch win, but this one came much easier.

He passed leader Dale Earnhardt Jr. with just over 50 miles to go, running him down and then sliding past when Earnhardt appeared to slow coming out of the fourth turn. There was no looking back from there for Kenseth, the 2003 series champion.

NASCAR changed the title-crowning format after Kenseth's championship, and he hasn't contended under the new 10-race playoff format. He used a win here last August to highlight a frantic rally to make the Chase, but faded when the playoffs began.

A repeat isn't likely for NASCAR's most consistent driver.

He's now second in points, and his back-to-back wins have sliced Jimmie Johnson's lead to just seven points.

"The guys are operating at a championship level," Kenseth said. "I was worried about going into the Chase and not running good. But this is what it's about, bringing your best piece and go there and try to win some races."

Kyle Busch finished second and was followed by Earnhardt, who had a terrible car when he arrived in Bristol and worked all weekend to salvage his title hopes.

"I am so proud of my team, they worked their butts off to turn a pile of crap into a good car," Earnhardt said.

Earnhardt, who came into the race in 10th in the standings — on the bubble of making the Chase — moved up one spot to relieve the playoff pressure.

"I feel a whole lot better now as far as trying to get in," he said. "All of us have really just got to watch what we are doing — minimize mistakes and utilize every minute of practice we get.

"I think we've got a really good shot of it. Before it was really just 50-50, up for grabs."