It was supposed to be Portland's first look at Kevin Durant, the player the Trail Blazers didn't take in the draft in favor of Greg Oden.
Instead, it was a routine, albeit close, exhibition game.
Durant, the No. 2 pick in the draft by the Seattle SuperSonics, sprained his ankle on Tuesday and didn't play Wednesday when the Blazers beat the Sonics 109-107.
Oden, the top draft pick, was already out for the season after microfracture surgery on his right knee.
LaMarcus Aldridge had 31 points and 13 rebounds for the Blazers. Brandon Roy added 22 points, 14 of those coming in the fourth quarter.
Chris Wilcox's 3-pointer put the Sonics up 49-48 before the break after trailing by as many as 13 points in the first half.
Luke Ridnour's fadeaway jumper extended Seattle's lead to 72-62. But the Blazers caught up late in the fourth quarter, when Aldridge hit a pair of free throws to narrow it to 101-99 with 2:03 remaining.
Portland kept it close until Martell Webster hit a 3-pointer to give the Blazers a 106-105 lead with 32.4 left.
After Luke Ridnour hit a pair of free throws with 23.2 seconds left to give Seattle back the lead, Roy answered with a jumper and Steve Blake added a free throw for the winning margin.
"We came together, especially in the fourth," Blazers guard Jarrett Jack said. "It's good to be tested in the preseason. We're just glad we could do it here at home."
The Blazers travel to the central Oregon town of Redmond for their final preseason game against the Denver Nuggets on Friday.
Nick Collison led Seattle with 17 points. The Sonics play the Phoenix Suns on Friday night in Vancouver.
"It's preseason so it's all good. You definitely want to win every game you play, but this is the preseason," Seattle forward Chris Wilcox said. "We're learning. We're working hard in practice but there are different situations in games."
Durant sprained his left ankle in an exhibition loss to the Golden State Warriors on Tuesday night.
The 19-year-old, who was the national player of the year in his only season at Texas, left the court with 2:10 remaining in the fourth quarter. He's averaged 18.8 points in the preseason.
Blazers edge Sonics as star rookies look on