The San Antonio Spurs know they can beat anybody when Tim Duncan and David Robinson are at their best. But tonight they turned in one of the surprising performances of the playoffs, routing Portland, 85-63, in Game 3 of the Western Conference finals with Duncan and Robinson combining for only five baskets.

Needing a victory at home to climb back into this series, the Trail Blazers picked the worst possible time to play their worst game of the season. Portland's 19 shots made were the fewest in NBA playoff history. Rasheed Wallace was the only Portland player to distinguish himself, hitting 7 of 11 shots.

Meanwhile, the Spurs got great perimeter play from Avery Johnson and Jaren Jackson. Although Robinson struggled offensively, he dominated the game at the other end by blocking seven shots. The result gave San Antonio a 3-0 lead in this best-of-seven series and a chance to complete the sweep Sunday.

"Not in my wildest imagination did I think we would win that way," Johnson said.

It was a game that left the Spurs feeling good about their resourcefulness and the Trail Blazers facing severe criticism, some of it internal, for an embarrassing home-court performance. Portland scored only 37 points in the final three quarters, and shot 24.7 percent (19 for 77) overall. If all that wasn't bad enough, the Trail Blazers have to face the fact that no team in NBA history has won a playoff series after losing the first three games. The Trail Blazers will be trying to hold off a San Antonio team that has won nine straight playoff games.

It also is unlikely that Duncan will play this little or this poorly again Sunday in Game 4. He played only 20 minutes and had as many fouls as points, five each. The San Antonio all-star, who averages 22 points a game, missed five of his seven shots. Robinson made only three field goals, yet it was never a contest after a 17-point San Antonio explosion in the third quarter. "If we can win by 20, I'll play two minutes," Duncan said. "I'll sit on the bench and clap the whole time."

Jackson led the Spurs with 19 points, hitting 6 of 11 three-pointers. Robinson hit 9 of 10 free throws to finish with 15 points. Johnson had 14 points and eight assists. Wallace scored 22 for Portland, but Isaiah Rider was the only other Trail Blazer in double figures with 10 points, but he missed eight of his 11 shots.

Even worse for Portland, forward Brian Grant didn't make a single basket, missing all five of his shots. Damon Stoudamire, who complained publicly this week about having to share playing time with Greg Anthony, missed 11 of his 12 shots in 29 minutes and was booed loudly in his home town.

"I don't know if it had an effect on our team," Stoudamire said of his comments. "I hope not, but maybe they did. The only thing I would take back is the timing of my comments. . . . [The fans] had the right to boo. I would have to if I was a fan and paid good money. I didn't play worth a damn."

Portland's biggest problem through the first 30 minutes was that only one Trail Blazer played anywhere near his potential: Wallace. The 6-foot-11 former Washington Bullet had 16 points and three rebounds early in the third quarter, and his aggression had kept his team and its fans even. But when he picked up his fourth foul early in the third and had to leave the floor, Portland fell apart completely.

Down 48-46 after Arvydas Sabonis hit a short shot, Portland wouldn't score again for seven minutes. San Antonio, in the third quarter, would outscore Portland 24-8 to take a 64-46 lead. Robinson's defense -- "He looked like he was eight feet tall," teammate Johnson said -- plus timely open shooting produced the 17-0 San Antonio run that iced the game.

"I feel bad for our fans," Anthony said. "They came wanting to cheer for us and root for us and we never gave them a reason to. I give their defense credit, but we were in such disarray, it was like a time bomb waiting to explode. Patience and poise go a long way and we displayed none of that tonight. . . . Let's not kid ourselves. We've got a lot of wounds we have to lick, a lot of pride that has to be regained. We have that opportunity on Sunday."

Box score on Page D9