Stewart raced to his second consecutive victory, and won for the fourth time in eight NASCAR Chase for the Sprint Cup races, finishing just ahead of points leader Carl Edwards in the so-called "Texas Title Fight" that fully lived up to its billing Sunday.
And Stewart backed up his challenge.
After winning last week at Martinsville, Stewart got out of his car in Victory Lane and said Edwards "better be worried. That's all I'm saying."
Now it looks like a two-driver fight for the championship with two races left after they finished 1-2 at the 1½-mile, high-banked Texas track.
Stewart cut his points deficit from eight points to three with an average speed of 152.705 mph, the fastest Cup race at Texas, and a 1.092-second margin over Edwards.
"We're set on it, man. This is just the way it's going to be," Stewart said. "I don't think we have to say anything (else). I think our performance today speaks for itself. He knows already, trust me."
The series returns next week to Phoenix, where the track has been reconfigured and resurfaced since Stewart was seventh and Edwards 28th there in February in the second race this season, and then to Homestead-Miami Speedway for the finale. Edwards won both races at the end of last season.
Sunday, Stewart led seven times for a race-high 173 of 334 laps, and more importantly stayed ahead of Edwards down the stretch.
On a restart with 60 laps to go after the second caution in a matter of laps, Edwards was the leader and on the inside of Stewart.
Coming out of Turn 2, Stewart shot by onto the backstretch and charged back to the lead.
"He timed it just right," Edwards said.
Stewart stayed in front until both made their final stops with 31 laps left. Though they dropped out of the 1-2 spots on the track during the cycle of green-flag stops, more importantly for Stewart was that he stayed ahead of Edwards.
During the first of the two cautions in a span of only six laps, Edwards had taken his first lead in more than 150 laps when he got only two tires and jumped from third to first out of the pits. Stewart also took only two tires on that stop, but came out second.
When Stewart came down pit road after the race, Edwards stuck his head in and shared a few words with his closest competitor.
"I just told him, 'Good job.' He did a great job today. Those guys stepped it up," Edwards said. "I'm proud of my guys for hanging on and still having the points lead. It looks like it's truly going to come down to Tony and I, and that's going to be a lot of fun."
Kyle Busch was officially eliminated from championship contention, unable to gain any points while watching his No. 18 Toyota going around the track from atop the pit box. He's 100 points back with two races left.
Michael McDowell drove the Joe Gibbs-owned car and finished 33rd.
Busch was parked by NASCAR — a rarely used penalty he couldn't appeal — for the Cup and Nationwide races after deliberating wrecking championship contender Ron Hornaday Jr. in the Truck Series race there Friday night. Busch issued an apology Saturday night and said he understood why he was penalized.
Five-time champion Jimmie Johnson moved closer to the end of his unprecedented championship run when he finished 14th. He remained sixth in points, 54 back.