The Bullets' National Basketball Association championship hopes suffered a crushing blow when Bob Dandridge's would-be game-winning shot spun around the rim and fell out just before the final buzzer yesterday.

Dandridge's miss from the corner let the Seattle SuperSonics salvage an emotional 93-92 upset at Capital and carry a commanding 2-1 lead in this final playoff round back to Seattle, where the series' next two games will be played tomorrow and Friday.

In what Washington Coach Dick Motta had called "the most important game in the history of the franchise," his guards made only nine of 45 shots thus allowing the Sonics to swarm all over the Bullets' inside attack in the second half.

As a result, Bullet forwards Dandridge and Elvin Hayes scored only a combined six points in the final quarter, leaving a frustrated Motta to say, "If you can't hit your outside shots, you don't deserve to win."

With Hayes, who totaled 29 points and 20 rebounds, and Dandridge, 21 points, unable to get the ball, the Bullets asked their guards to deliver down the stretch.

But none of them could respond. For the game, Kevin Grevey, sore-legged and in the throes of a deeph shooting slump, was one of 14 from the field; Tom Henderson six of 18; Charles Johnson two of 10; Larry Wright zero for three. Of their nine field goals, only three were from beyond 10 feet.

Yet Washington, despite 34 percent shooting and careless defense, almost pulled out victory because Seattle made two careless turnovers in the final eight seconds.

The first came with the Sonics ahead, 93-90. Dennis Johnson, the game's most spectacular defensive player with seven shot blocks, tried to toss a long inbound pass from under his defensive basket. It was picked off at the foul line by Henderson, who drove the length of the floor for a layup with three seconds left.

Referee Earl Strom then called veteran forward Paul Silas for stepping over the inbounds line on Seattle's ensuing throw-in from the Bullets' offensive end.

Silas said he wasn't sure he had committed the error. A CBS spokesman claimed a videotape replay of the incident showed no violation. But Strom countered that there was "no question. He straddled the line."

Whatever, the Bullets had the ball with three seconds left and what was left of the sellout crowd of 19,033 was up and cheering while Motta decided whether he should call a timeout.

"If I did, it would have meant a technical because I didn't have any left," he said. "That would have meant we were playing for a tie. But we got things squared away and I decided to forget stopping play."

What Motta wanted was a clear shot off the Bullets' standard out-of-bounds play. And he got exactly what he had asked for: Dandridge grabbed the inbound pass and turned for an open 20-footer from the left corner.

"It went in and it came back out," Dandridge remembered. "It went around the rim. When there is that much time left, your main objective is to get off a good shot. We achieved that, but it just didn't go down."

Motta said he thought the shot "was in the hole. I had already looked at the clock to see how much time was left because the buzzer hadn't sounded. It was in and out." STAs Dandridge's shot was going around the basket, Haye's hands were above the rim, trying to guide it in. Silas thought Hayes had touched the ball on its downward flight; Hayes denied it. When the ball finally squirted out, Silas pulled it in as the buzzer went off.

"We just were in our regular offensive patter," Dandridge said. "It was a set play from out of bounds, and it just so happened I was in the position to shoot it. Wes(Unseld) set the pick and I got the open shot.

"When it left my hands I thought it was going down. When it went out, I knew it was all over."

Did Hayes, who was in position, to rebound, touch the ball in the air or on the rim? Dandridge was asked.

"No," he said emphatically. "It just came out of the basket. It didn't look like he hit it, not to me. I don't think anyone interfered with it. It was a tough shot. Sometimes they go, sometimes they don't."

The Bullets now have to win three of the next four games to capture the championship, including two of three in Seattle, where the Sonics have won 21 straight. The Tuesday night game will be played in the indoor baseball-football complex called the Kingdome rather than the Collseum, the Sonics' regular home court.

"We aren't going to win it if the guards don't start shooting," said Charles Johnson. "It's as simple as that."

Washington had contrived to win game two here Thursday night despite a poor performance from every guard except Henderson, who made 20 points. But yesterday, none of the back-court members were effective despite, according to Grevey, "Seattle giving us the perimeter shots we normally hit."

By the fourth quarter, the Sonics virtually conceded any Bullet shots from 18 feet and beyond while they swarmed around Hayes and Dandridge and cut off any inside passes. Dandridge got off five shots in the final 12 minutes, missing every one. Hayes made two of three - all layups.

"They clogged the middle on us, they were just about in a zone," Motta said. "We had the shots we usually put in from out there."

Motta said he felt comfortable at halftime despite a 49-47 deficit "because we shot only 33 percent and our guards were one for 14 at one point. I felt the shots had to start dropping.

They did not. And the Sonics started taking advantage of the Bullets' bad marksmanship by getting their fast break untracked and pulling away to a 78-70 lead early in the fourth quarter via a 10-2 spurt.

Dennis Johnson scored five of those points off two fast breaks, one of which was set up by his block of a Charles Johnson shot.

"We didn't adjust too well to (Dennis) Johnson flying in the air and blocking shots," said Motta. "He really hurt us."

But both Charles Johnson and Grevey, who had his sore knee drained before the game, kept challenging the Sonic guard. He wound up blocking five shots just in the fourth quarter.

When the Sonics held a nine-point lead with four minutes to go, many in the crowd headed for the exits. But a rebound lay-in by Hayes, a fast-break jumper by Mitch Kupchak and a foul shot by Dandridge pulled the Bullets within four.

Seattle's Fred Brown missed an awkward one-hander and Motta called time with 1:39 left. He set up a play to get the ball to Hayes, but the strategy never got a chance to unfold. Brown picked off Charles Johnson's pass just inside halfcourt and raced off for a breakaway layup.

"We were still in it until that turnover," Motta mourned. "But that put us in the hole."