Roy, who scored 42 points in Portland's 107-103 win in Game 2, had 19 points, but went 6-for-18 from the field. Steve Blake scored 16 and had 10 assists, and Rudy Fernandez sank five 3-pointers and finished with 17 points for the Blazers, who trailed by 17 in the second half before rallying in the final quarter.
The Rockets led by nine before Roy converted a three-point play and tipped in a miss by Travis Outlaw to make it 78-74.
Scola hit a mid-range jumper with a minute left and Roy missed a running one-hander. But Portland rebounded, called timeout with 32 seconds left and LaMarcus Aldridge sank a 3-pointer to cut Houston's lead to three. Aldridge scored 13 in the game.
Roy fouled out with 20 seconds left and Aaron Brooks hit a free throw for an 81-77 lead. Fernandez swished a 3-pointer from the corner and Brooks hit two more free throws with 16 seconds left.
Blake badly missed a 3-point try and the Rockets sealed it from the free-throw line in the closing seconds.
Ron Artest and Battier teamed up to blanket Roy all night, bumping him almost every time he touched the ball.
The Blazers tried to be physical, too, especially on Yao. Joel Przybilla earned a technical foul in the first quarter for delivering an extra shove on Yao, who scored only seven in the game.
But most of Portland's problems came at the other end - the Blazers started 4-for-16 from the field.
Yao was out early in the second quarter and Scola hit a jumper and converted a three-point play. The Rockets hit six straight shots, including a breakaway dunk by Von Wafer, to stretch the lead to 34-22.
Yao replaced Scola midway through the second quarter and Wafer finished the Rockets' next possession with a driving dunk. Houston went 12-for-15 from the field in the quarter.
The Blazers never found their range in the first half and trailed 48-37 at the break. Roy was 2-for-7 from the field and Aldridge, who scored 27 points in Game 2, was 2-for-8.
Aldridge was called for an offensive foul in the first minute of the second half and Yao flipped an assist to Battier for an easy layup.
