Like the buildup in a suspense-filled novel, Matt Kenseth is on the verge of reaching the best part of the story.

If everything goes well for him in Sunday's Checker Auto Parts 500, Kenseth will leave Phoenix International Raceway just one race from clinching his first -- and the final -- Winston Cup championship.

Right now, there's little Kenseth's top chasers -- Dale Earnhardt Jr., Kevin Harvick and Jimmie Johnson -- can do to catch him. It's not so much his championship to win as it is his to lose. With a commanding 258-point lead over Earnhardt, Kenseth just has to continue what he's done all season -- namely, be consistent -- and the title will be his.

"Dale Jr.'s been running real good lately, and I know he got around Kevin and everything," Kenseth said of Earnhardt overtaking Harvick in the standings at Monday's rain-delayed race in Atlanta. "Yeah, that's quite a few points, but anything can happen. There's three races to go and we've been real strong at Phoenix in the past and at Rockingham, so I'm looking forward to that."

While Kenseth's 258-point lead in the championship appears comfortable, he doesn't have to think back very far to see just how precarious a so-called comfortable lead can be. He came into Talladega in late September with a seemingly insurmountable 429-point lead.

Speculation wasn't about whether Kenseth would win the championship, but how quickly he'd do it. Some even had him taking home the final Winston Cup trophy (the series shifts to Nextel sponsorship next season) as early as Martinsville (two weeks ago) or Atlanta (last week).

But fate suddenly threw a socket wrench into Kenseth's title hopes, if not throwing a full-blown scare. In back-to-back races -- at Talladega and Kansas -- he suffered his two worst performances of the season, 33rd and 36th respectively, and saw his commanding 429-point margin quickly slip to 252 points with six races remaining.

Fortunately, Kenseth went back to his consistent ways in the next three races, finishing eighth at Charlotte, 13th at Martinsville and 11th in the rain-delayed race at Atlanta this past Monday.

Which brings him full-circle back to Phoenix, where he won last year's race. While he could clinch the title this Sunday, it would require an incredible amount of luck for him and misfortune for his top three challengers, Earnhardt Jr. (258 points behind), Harvick (262 points behind) and Johnson (266 points behind).

Kenseth would have to win the race, while Earnhardt Jr., Harvick and Johnson would all have to drop out in the early stages or finish at the back of the pack. Kenseth, who would also need to out-point Jeff Gordon to win the title on Sunday, would have to leave Phoenix with a 371-point advantage to clinch the championship.

But Earnhardt Jr., Harvick and Johnson aren't just going to roll over. With the championship pretty much out of reach, they're locked in another battle, the fight for second-place. And with only eight points separating the trio, and with Gordon, the winner of the last two races, only 30 points behind teammate Johnson, the fight for runner-up could prove to be just as exciting as when Kenseth finally does clinch the title.

	“	We're not going to celebrate until it's a done deal, but we're ready. ”
		— Matt Kenseth on his Cup quest

While Kenseth won't have the same winning car that he drove in last year's race, he and crew chief Robbie Reiser are definitely bringing all the notes and data they compiled from last year's foray into Victory Lane.

And, they're also bringing out a little added muscle.

"We're bringing Chassis No. 23, which we've used everywhere, it seems," Reiser said of the same car that has four top-10 finishes in as many starts for Kenseth this season. "It's a great car. We're looking to defend our title and get us another win before the year is out."

Added Kenseth, "Last year was a big win for us. We've always run pretty well (at Phoenix) in the past and I've been looking forward to going back."

There's other motivation for Kenseth this weekend. Besides closing in on the championship, he'll take home a cool $340,000 Winston Cup leader bonus if he wins Sunday's race, awarded when the standings leader wins the race. Kenseth only has one victory in 2003, at Las Vegas in the third race of the season.

But what he's lacked in wins, the Wisconsin native has more than made up for with incredible consistency. He's been atop the standings for the past 30 weeks and has a series-leading 23 top-10 finishes

Phoenix is not only the site of Kenseth's win last year, it was also the site of the first career Cup win for the late Alan Kulwicki, who was a Wisconsin native like Kenseth. Kulwicki's win at Phoenix in 1988, the first of five career Cup wins before he tragically died in a plane crash in April 1993 while on final landing approach to Bristol, Tenn., will forever be known in NASCAR lore for his so-called "Polish Victory Lap," when Kulwicki did the traditional post-victory lap backwards.

Kulwicki has been an inspiration for Kenseth, not only because they were natives of America's Dairyland, but also because they came from middle-class, blue collar roots. Kulwicki eventually went on to win the 1992 Winston Cup championship, defeating Bill Elliott by just 10 points in the final standings, stealing the title on the final day of the season, a record that still stands for the closest championship race in Cup history.

Now it's Kenseth's turn to show the good old boys of Winston Cup that another Yankee is ready to take his place among Cup champions.

"We're not going to celebrate until it's a done deal, but we're ready," Kenseth said.

Jerry Bonkowski covers NASCAR for ESPN.com. He can be reached at Motorsportwriter@MSN.com.