Anfernee Simons led all scorers with 30 points, including seven 3-pointers, for the Blazers, who led by as many as 18 points. With the win, Portland improved to 5-1 this season.
"It's easy for guys to to get relaxed, but where we want to get to, you can't do that. But all in all I think we played a good game, closed it out in the end, made a run and opened the lead up," Simons said.
"We should have been frustrated with the way we played, especially in the fist half, Rockets coach Stephen Silas said. "We're putting a lot of pressure on our offsense because of our defense. ... Not a good night. We've got to do better."
Lillard, Portland's six-time All-Star, strained his right calf on Wednesday night against the Miami Heat. The team said he will re-evaluated in one to two weeks.
Lillard came up limping with some five minutes to go in the third quarter and headed for the locker room. He did not return and the Blazers lost, 119-98. Afterward, Lillard said he was hopeful that treatment would allow him to return for Wednesday night's game against the Memphis Grizzlies.
Rookie Shaedon Sharpe made his first start for the Blazers, and Simons moved to point guard in Lillard's absence. Sharpe finished with 14 points, but admitted at first he was a bit nervous.
"But once tipoff happened, just started relaxing, just played the game I know how to play within the team and everything, just tried to get my teammates the ball, offensive and defensive side," Sharpe said.
Alperen Sengun, who missed the last two games because of illness, made his first start of the season for the Rockets. Porter, who has been dealing with a right quad contusion, also started.
Portland jumped out to to a 29-16 lead in the opening quarter after Drew Eubanks' dunk.
Sharpe had back-to-back dunks in the second to give Portland a 45-34 lead and put the crowd on its feet. The Blazers went on to lead 69-58 at the break.
"You just never know what he's going to do when he gets that runway like that," Blazers coach Chauncey Billups said about Sharpe. "He made a couple of plays that got the crowd going. But I thought he was solid overall.
The Rockets closed to 74-69 on Sengun's basket, but it was as close as they could get in the third quarter and Portland led 96-82 going into the final period.
Nurkic made had his first 3-pointer of the season to put Portland up 107-93. The Rockets narrowed the gap to 112-104 with just over five minutes to go in the game.
Rockets: Rookie TyTy Washington Jr. missed a sixth game with a left knee sprain. ... It was the second of a four-game road trip for the Rockets, who are on a stretch where they play eight of nine away from home. ... Jae-Sean Tate fouled out with 3:57 left in the game.
Trail Blazers: Portland split the series with the Rockets last season 2-2. ... Simons had seven 3-pointers in the first half.
Rockets: At Phoenix on Sunday.
Trail Blazers: Host Memphis on Wednesday.