HOMESTEAD, Fla. -- His official title is "crew chief," but Greg Zipadelli has proven to be so much more in Tony Stewart's quest for his first Winston Cup championship.

In his role, Zipadelli wears more caps than most other crew chiefs. Like most, he oversees the maintenance and construction of the cars, their performance and testing, as well as rides shotgun over race strategy from the pits on race day.

	Greg Zipadelli, right, is more than just Tony Stewart's crew chief, he's Stewart's friend.

But the 35-year-old "Zippy," as he's affectionately known, also has the sometimes arduous task of keeping the often headstrong Stewart under control.

And, to top that all off, Stewart and Zipadelli have to keep all their horses reigned in for Sunday's season finale, the Ford 400 at Homestead-Miami Speedway. For, even though Stewart holds an 89-point edge over Mark Martin, Zipadelli knows anything can happen.

The best example of that was 10 years ago, when the top-five drivers entered the final race of the 1992 season separated by just 98 points. Going into the race, it was anyone's title until Alan Kulwicki came out on top, winning the championship over Bill Elliott by 10 points, the closest finish in history.

Zipadelli worries that a scenario like that could play out Sunday if Stewart falters and Martin capitalizes to steal the trophy out of Stewart's grasp. In and of itself, Sunday's race could be the most important Zipadelli has called in his career. One wrong move, and Stewart's championship hopes could go up in smoke.

"There are struggles at times, because there is plenty of weight (on the team's shoulders)," Zipadelli said. "That is one of those things that -- I don't want to say 'enjoyed' -- but have been able to deal well with. There is just a lot on your plate.

"But, we're just going to take it one day at a time. We're going to continue to do the things that got us where we're at, head to Homestead and honestly, truly, try to win that race. I feel like we've got a driver that is more than capable. He loves that racetrack. Our cars and setups normally seem to work really well there. If we can and do that, we won't have to worry about the championship. It'll just happen."

Stewart's track record at Homestead speaks for itself: He won the first two events there in 1999 and 2000, and had a chance at winning last year's race before he and Zipadelli got into a dispute on the radio over tire strategy.

Stewart ignored Zipadelli's instructions, did what he wanted to do, illegally drove on the grass to find pit road during the last caution of that race to change a bad set of tires, and it cost him dearly. NASCAR responded with a stop-and-go penalty, dropping Stewart, who led 72 laps, to the back of the longest line on the restart and effectively ending Stewart's hopes for a three-peat.

As it turned out, Stewart's chance of a win evaporated into a disappointing 19th-place showing.

You can best believe, however, that a repeat won't be seen Sunday. With the championship on the line, Zipadelli will make all the calls and Stewart will dutifully listen and adhere to them. If he doesn't, Stewart can quite likely forget about being crowned champion.

"We haven't had very many issues of disagreeing or not dealing with each other," Zipadelli said. "(Homestead last year) was a circumstance where we put a set of tires on that was absolutely horrendous and (Stewart) wasn't looking at the big picture. I was.

"A top-10 that day would have locked us, probably, going into Loudon (the following week) into second place, rather than beating him out by five or 15 points, or whatever it was. Those are the things we look at more now, that when you make those decisions, you have to look at the big picture. We've always been good at just winning races and worrying about running good that day and not worrying about the big picture.

	“	Truly, I think it is a huge asset to our team, that I'm not only a good friend to Tony, but all my guys are -- whether it be fishing, go-kart riding, goofing around. We all have that relationship. ”
		— Zipadelli

"In order to win a Winston Cup championship, you have to start the season by looking at that big picture and trying to do the right thing all the time to accumulate as many points as you can."

In testing at Homestead two weeks ago, Stewart turned in blistering speeds, leading all drivers. Based on the strength of that test, not to mention his previous two wins there, Stewart has to be the favorite to win Sunday's race.

As he wraps up his fourth full Winston Cup season -- and likely the first of several championships -- Stewart has achieved his accomplishments in one of the hardest ways possible. His noted temper flared up after the Brickyard 400, when he had a physical confrontation with a photographer that resulted in $60,000 in fines and probation.

If Stewart slipped up once more during the season, he was gone.

To his credit, Stewart has been a picture of responsibility since Indianapolis and the resulting costly fallout. He has avoided any scrapes on or off the track, toned down his anger and become a model racer, for the most part.

"In Winston Cup racing you're going to have a lot of tough weeks and (the week after Indianapolis) might have been this team's toughest week," Zipadelli said. "But, we all sat and talked about it and thought long and hard about it, and what got us to the point that we were at -- a great part of that was Tony. We all know him a lot better than everybody else because we know him outside this world, and he is honestly and truly one of the best people I have gotten to know, hang out with, have fun with.

"I think it just shows how strong this team is and how strong he is. That had to be an extremely mental week for him. He had to show up and focus on everything. Everybody was poking and prodding at him for all that had happened the week before. He handled it well, went on and did what he was supposed to do - get in that car, drive it to the best of his ability and did a great job for us."

That may be an understatement -- Stewart won the next week at Watkins Glen, N.Y.

And a "great job" is what Zipadelli will be looking for in Homestead, with the championship, the end of Stewart's probation and the culmination of what has turned from a nightmare to a dream on the line for Stewart, Zipadelli and the rest of the team.

"You don't spend that much time with somebody, count on them, have them believe in you and have them trust in me without us being good friends," Zipadelli said. "I particularly have not been in any situations where it was just a driver, that was it -- come in, do your job, weren't good friends, didn't work hard at just doing things that normal people would do.

"Truly, I think it is a huge asset to our team, that I'm not only a good friend to Tony, but all my guys are -- whether it be fishing, go-kart riding, goofing around. We all have that relationship. I think when times get tough, sometimes it's easier to deal with some things because you're hanging out with friends. You're hanging out with people that you truly, honestly care about and love. I treat Tony, and think of him, as my brother."

Stewart acknowledges the impact Zipadelli has played not only in his career, but in making the team a winner.

"Greg is the one person that has probably been the driving force behind us being where we are," Stewart said. "He has been a much larger leader in our race team than I have.

"With all the other people I've ever been associated with in racing, he cares more about me as a person than he does a race car driver. Joe has always had the same approach. That's not an attitude that you see with a lot of car owners or crews. You're a piece of property at this level to a lot of people. The one thing about Joe, and especially Zippy, is that they care about me more as Tony Stewart, the human being, than Tony Stewart the race car driver."

Jerry Bonkowski covers NASCAR for ESPN.com.