Jake Layman scored 23 points and grabbed seven rebounds to lead the Trail Blazers to a 94-87 victory over San Antonio on Saturday in Las Vegas Summer League action.
Caleb Swanigan and R.J. Hunter each added 16 points for Portland, which advances to Sunday's semifinals against Memphis, which beat Miami, 98-95, in two overtimes.
Swanigan had 14 of his points in the first half to help stake the Blazers to a 47-40 lead at intermission.
The Spurs scored the final 10 points of the third quarter to tie the count at 65-65.
Portland scored the first six points of the fourth quarter and never looked back.
The Blazers won the rebound battle, 48-31, and benefited from 20 San Antonio turnovers.
Derrick White came off the bench to lead the Spurs with 20 points. Guard Bryn Forbes — who came in averaging 29.2 points in the tournament — added 13 but made only 2 of 8 shots and fouled out in the fourth quarter.
Portland and Memphis will play at 3 p.m. Sunday, with the Los Angeles Lakers taking on Dallas in the 5 p.m. semifinal at Thomas and Mack Center.