As spectacularly as they started, the Rockets defeated the Pistons 91-85 before 17,345 at Toyota Center on Thursday with how they finished.

They had lost all but the last four points of a 17-point fourth quarter lead, but the Rockets recovered just in time, with a Rafer Alston drive, Tracy McGrady jumper and Yao Ming block closing out the Pistons.

The Rockets had led by 15 with 5 1/2 minutes remaining, but the Pistons scored on each of their next five possessions in a 13-2 run capped by a Chauncey Billups 3-pointer that reduced the Rockets' lead to 86-82.

McGrady had missed all three of his fourth-quarter shots. Yao had just hit a jumper, but that had made him just 2-of-5 in the quarter after he had made 8 of 13 shots for 23 points through three quarters when the Rockets led by as much as 20. He finished with 27, making 10 of 19 shots.

Alston, who made five of seven shots for 16 points with six rebounds and six assists, sank a runner in the lane to interrupt the Pistons' run, and after a Billups free throw, McGrady put in a baseline jumper. But the Rockets could not get the stops they had to have until the final minute.

After an Antonio McDyess jumper reduced the Rockets' lead to five, Carlos Delfino broke down the lane and toward the rim, only to have Yao meet him to swat away his shot. Yao's first block of the night came with 22 seconds remaining.

The Pistons immediately put Alston at the line and he made his second free throw for a six-point lead with 17.3 seconds left. Rasheed Wallace missed a 3, but when McGrady missed both free throws with 11.1 seconds left, the Pistons had a glimmer of hope.

That ended when Delfino, assuming Yao would come to meet him again, missed a layup, and the Pistons let the final 5.9 seconds run out.

After scoring the first 10 points of the first half, the Rockets scored 8 of the first 10 of the second half, taking their lead to 56-37 less than three minutes into the second half.

After a Billups technical foul, Yao sank a free throw for a 20-point lead with five minutes still left in the third quarter. That did not last long, but the Rockets kept the Pistons well off their pace, only briefly within 15, and trailing, 73-56, heading into the fourth quarter.

The Pistons came in with one of the league's best road records, but with a fourth-quarter lead at home, the Rockets were 23-3 when leading after three quarters.

Still, after Rafer Alston began the fourth quarter with a drive that pushed the lead back to 19, the Rockets began to crack. It took more than three minutes before they scored again, with Alston sinking a 3. Ronald Murray and Antonio McDyess each hit jumpers. Delfino put in a corner 3. And the Pistons had a 7-2 run to reduce the lead to 13, with 7 1/2 minutes left.

That brought Tracy McGrady, Shane Battier and Chuck Hayes in off the bench, with Yao needing a break. And that brought a quick surge. But with the Rockets leading by 15, Delfino sank a 3 and Wallace put in a pair of free throws.

McGrady missed a jumper and Yao came back in to airball another, before Billups drove to three-point play, reducing the Rockets' lead to 84-77. With 3:50 left, the lead was much too small, with much too much time remaining for the Rockets to simply hold on.

The Rockets got off to a dream of a start, scoring the game's first 10 points and making 5 of 7 shots while the Pistons missed their first seven attempts.

After the Pistons finally scored, Shane Battier sank a 3-pointer and Yao put in a jumper and a free throw for the Rockets' largest lead of the half, 16-2, less than six minutes into the game.

The Pistons, however, never showed a hint of alarm with a rapid start.

They scored the next eight points, and when Tayshaun Prince began the second quarter with a strong drive, Detroit had closed to within 20-17. And as quickly as the Rockets had started, with Yao making each of his three first-quarter attempts, Yao had picked up two fouls in the game's first 90 seconds.

He stayed in the game with two fouls and played 8 1/2 minutes n the first quarter, returning in the second quarter to help the Rockets regain some control.

When the Rockets began the second half nearly as rapidly as they had the first, they immediately began to pull away.

The easy win, however, would not last. Instead, they had to win it the hard way.