Linebacker Shelton Robinson got slow-starting Seattle going with a 12-yard fumble return for a touchdown today and the underdog Seahawks defeated Los Angeles, 34-21, for their second victory over the Raiders in three weeks.

"I don't know what it is about Seattle," said Raiders Coach Tom Flores. "We always seem to have trouble with them . . . , but they are a good football team. They've beaten some good teams, including us twice. We didn't take them lightly."

Robinson, who returned a fumble for a touchdown in the 38-36 victory over the Raiders (6-3) Oct. 16, made his big play with 9:18 left in the second quarter and the Seahawks (5-4) trailing, 7-0. Linebacker Keith Butler shook the ball loose from running back Marcus Allen and Robinson scooped it up.

Seattle quarterback David Krieg, making his first start this season and the sixth of his NFL career, completed 13 of 22 passes for 156 yards and one touchdown. Jim Zorn, whom Krieg replaced, threw a 33-yard touchdown pass off a fake field goal and rookie running back Curt Warner gained 101 yards on 23 carries and scored once. The Raiders' Marc Wilson was intercepted four times.

The Raiders took a 7-0 lead on Allen's one-yard run on the first play of the second quarter. In the first 15 minutes, Los Angeles had eight first downs to Seattle's none and 110 yards to 13. But Norm Johnson put the Seahawks ahead to stay when he kicked a 37-yard field goal with 3:49 left before halftime. It became 17-7 on Krieg's five-yard touchdown pass to tight end Charle Young with 12 seconds left in the half.

The Raiders drove 46 yards in seven plays on their first possession of the second half, scoring on Wilson's four-yard pass to tight end Don Hasselbeck. But the Seahawks went 65 yards in 10 plays, Warner scoring on a fourth-down, one-yard sweep.

The Seahawks extended their advantage to 17 points with 11:49 left in the game on Zorn's 33-yard pass to running back David Hughes on the fake field goal.