With the largest audience in NBA history looking on in Seattle Tuesday night, Richard Washington delivered a performance that should earn him a nomination as basketball's best big man in a supporting role.

Washington came off the bench to score 21 points and spark the surging Milwaukee Bucks to a 108-97 triumph over the Seatle SuperSonics before a disappointed throng of 40,172 in the Kingdome.

"I've gotten a lot of criticism from the media and other people," said the 6-foot-11 Washington, a fourth-year pro from UCLA. "But I've never lost my confidence. Maybe now some of those people will be saying: 'The guy can play.'"

The triumph gave Milwaukee a 3-2 edge over the defending NBA champs in their Western Conference semifinal series. A victory Friday in Milwaukee will send the Bucks into a best-of-seven series for the conference tite with the Los Angeles Lakers.

Washington, who averaged just under six points a game in the regular season, shot well from the perimeter as he connected on 10 of 12 field-goal attempts. Primarily a forward, Washington replaced the injured Harvey Catchings as Milwaukee's backup center for Tuesday's contest.

Washington hit four quick field goals when he replaced Bob Lenier in the last four minutes of the third period as Milwaukee ran off a 14-5 streak to take an 85-72 lead into the final period.

Fred Brown scored nine points and rookie James Bailey added four as Seattle fought back to close the gap to 92-89 with 4:20 to go.

But Lanier hit a foul shot. Marques Johnson followed with a dunk and Washington added a three-point play as the Bucks ripped off six straight points to build their lead to 98-89 with 2:37 left.

The victory, however, could prove costly to Milwaukee.

Starting forward Dave Meyers sat out the entire fourth quarter with a sore left knee after he got tangled up with a teammate, and sixth man Junior Bridgeman was carried off the court on a stretcher after a collision with Seattle's Jack Sikma in the final period.

Bridgeman was taken to Seattle's Swedish Hospital complaining of lower-back pain. Bridgeman, who was x-rayed and kept in the hospital overnight for observation, was listed in satisfactory condition.