HOUSTON (AP) -- On the brink of his first win as coach of the Houston Texans, Gary Kubiak couldn't bear to look.
Too bad, because if he'd turned around he would have seen No. 1 draft pick Mario Williams make a game-saving play. Williams tipped a two-point conversion that would have tied the game and finally got his first sack as the Texans beat Miami 17-15 on Sunday.
The Dolphins trailed 17-9 when Daunte Culpepper found Chris Chambers for a 16-yard touchdown with 1:39 to go to pull within two. Miami went for the 2-point conversion, but the pass by running back Ronnie Brown was tipped by Williams and sailed over Chambers' head.
"He threw it and I just reached up and tipped it," Williams said. "I was in the right place at the right time."
The Dolphins (1-3) tried an onside kick and almost recovered, but the ball squirted out from underneath Keith Adams and the Texans fell on it and ran out the clock.
"That was pretty cowardly," Kubiak said, referring to his turning away from the play. "I've been that way in football through a lot of things. I'll make a call and just walk away. I heard everybody go crazy, so I knew it was good. That was a great sound."
After Carr's 1-yard score put Houston (1-3) ahead 10-6 early in the fourth, Williams got to Culpepper for a 3-yard loss. The sack was the first of his career and his first tackle of the game.
Williams jumped for joy and hugged a teammate as the crowd responded with a standing ovation.
"Now you can't say I don't have a sack," Williams said. "It was a good thing, but at the same time, playing a game and putting the pressure on him, that was a great ending to get a sack."
On the next play, Williams and fellow rookie DeMeco Ryans combined to take Culpepper down again, this time for a 7-yard loss. The Dolphins were forced to punt and the Texans responded with another touchdown, this one a 3-yard catch by Andre Johnson that lengthened the lead to 17-6.
Johnson finished with nine receptions for 101 yards.
The Texans found a pass rush against the Dolphins, sacking Culpepper on the first play of the game and harassing him all day. Houston had just three sacks entering the game but got to Culpepper five times. The less-mobile Culpepper has been sacked 21 times this season in his return from reconstructive knee surgery.
He was 23-of-39 for 249 yards and a touchdown.
"We know we're a better offense than we played today for the first three quarters," Culpepper said. "We just waited a little too late to put on a surge."
Kubiak's first win came against a defense led by former Houston coach Dom Capers, who was fired by Houston in January after a 2-14 season. It broke a five-game losing streak dating to last season.
The game was an ugly defensive struggle for most of the first three quarters, with neither team managing a touchdown and the Dolphins' field goals coming off Texans turnovers. It was 3-3 at halftime.
"I told our players that when you play teams this time in the season that haven't won a game, they're very dangerous teams," Dolphins coach Nick Saban said. "They're a little bit like where they want to prove something ... and I think their team played awfully well today."
The Dolphins took the lead on a 29-yard field goal by Olindo Mare in the third quarter that was set up by a 19-yard fumble return by Jason Taylor, who sacked Carr and stripped the ball before recovering it.
Houston finally took the lead on a 10-play, 70-yard drive that ended with Carr's run. The defense bit on a fake to Ron Dayne and Carr trotted into the end zone untouched before celebrating by throwing the ball high up into the stands.
Carr completed 22 of 29 passes for 230 yards with an interception and was also sacked five times.
Will Allen grabbed the ball out of Johnson's hands for an interception in the second quarter. But the Dolphins couldn't move the ball and had to settle for a 52-yard field goal by Mare.
Mare kicked his 14th field goal of 50 yards or longer, tying the Dolphins record held by Pete Stoyanovich. ... Johnson had the 12th 100-yard receiving game of his career.