CONCORD, N.C. - Elliott Sadler, who declared his championship hopes all but over two weeks ago, vaulted back into the points chase last week and could leave tonight's UAW-GM Quality 500 at Lowe's Motor Speedway as the new series leader.

Almost halfway through NASCAR's inaugural championship chase Sadler admits he's experienced "every emotion that I think a human can possibly have." He's not alone. NASCAR's 10-race title run has frustrated competitors and thrilled others. Five of the 10 contenders could leave tonight's race with the points lead that Kurt Busch holds. With so few races remaining, every mistake is magnified, every victory a relief.

And five races remain after tonight. Five more chances for heartache. Five more chances to celebrate.

This year's champion might be the driver who best handles the stress.

That's something everyone feels, including four-time champion Jeff Gordon.

"When the car is not handling the way you want it to, it seems like your frustration level goes to an all-time high because you know how critical it is to be good ... throughout the entire race," said Gordon, who is third in the standings, 79 points behind Busch.

"You're pushing everything, including your nerves."

Mark Martin said he's felt more pressure this season than any other time during a career in which he's finished second in the points four times.

"It's more difficult to compete on the same level that we did before because other people are working harder at it, too," he said.

Nowhere has the stress been as heavy as with Jimmie Johnson and his team. Johnson was either first or second in the points 18 consecutive weeks before the chase started. He's not been higher than fourth in the points since the chase began at New Hampshire last month. He enters tonight's race in ninth, 247 points behind Busch.

"Our championship hopes are in the hands of the other guys, and if they don't have a bad race or two, there's nothing we can possibly do about it," Johnson said. "At one point in the year I think we looked pretty much unbeatable and now that's definitely not the case. We're working hard ... and trying to get the magic we had back."

Ryan Newman also shares Johnson's frustrations. The last driver to qualify for the chase, he has not been higher than seventh in the standings despite a win during this stretch.

"You've got to let it go after one bad race or two bad races because there are more races ahead," he said. "Until we're at Homestead [for the season finale] we'll just keep our smiley face on and do the best job we can."

It's one thing to say, another thing to do.

"It's not easy to do by any means, but it's what you have to do," Newman said. "You have to forget about what you can't fix."

Few are immune, even Busch, who holds a 29-point lead on Dale Earnhardt Jr. Busch has never scored a top-10 finish at Lowe's Motor Speedway and he brushed the wall in the final practice session Friday night. It wasn't enough to force the team to go to a backup car, though.

Last week after the Kansas race, Busch acknowledged that his lead could be tenuous.

"With this Nextel Chase for the Cup, we've been given a second opportunity, but we know we can lose it just that quickly," he said.

Sadler, who trails Busch by 143 points, knows what Busch is saying. Yet, it didn't dampen Sadler's mood Friday night after recording the fastest lap in the final practice session.

"It's by far the best car I've ever had at Charlotte," he said after quitting the session early.

Yet, in this emotionally churning chase, will Sadler feel the same way tonight?