The Seattle SuperSonics rallied from a 19-point third-period deficit yesterday to beat Washington in game one of the NBA championship series, 106-102, giving the Bullets what Bob Dandridge called "a lesson in pro basketball we didn't need."

The lesson was taught largely by Sonic reserve guard Fred Brown, who scored 30 points in 33 minutes, 16 of those points in the final 9 1/2 minutes. Brown hit seven of nine shots in the pivotal fourth quarter, including a 25-footer with 14 seconds left to finish off the Eastern champions.

The Bullets' leading scorer in the game, Kevin Grevey, 27 points left the game late in the fourth quarter with a sprained left ankle, but he is expected to play in game two Thursday in Capital Centre.

"I'm going to play," Grevey said. "It's not hurt too badly. I've been through this before." But Bullet trainer John Lally said the extent of the injury would be determined today.

Meanwhile, other Bullets were counting the lessons learned in game one.

"This game is an example of what can happen in this league," said Bullet forward Dandridge. "If you get complacent when you get ahead and let down, you can lose a lead. All of us know that, but it didn't do any good today."

For almost three quarters, the Bullets had everything the way they wanted. They controlled the tempo, forced the SuperSonics out of their offense and made 60 percent of their shots.

Just as quickly, they lost their touch and Seattle, which has specialized in fourth-quarter rallies this season, exploded.

From 84-65, Washington, with 2:26 left in the third period, the Sonics took charge in the next six minutes to outscore the Bullets, 19-2, and close the gap to 86-84.

Then Brown, who thrives on pressure, applied the knockout punch in the last two minutes over Charles Johnson to pull Seattle within a point at 102-101. After two Dennis Johnson foul shots gave the Sonics a 103-102 margin, Brown went to work on Larry Wright, who had missed a 20-footer at the other end.

Brown, the man they call "Downtown" for his long-range shooting, watched the shot clock as he backed in against the smaller Wright. He turned and failed on a jumper, but the longer rebound was controlled by Seattle forward Paul Silas and Brown again got the ball with 30 seconds to go.

"I was very tired," Brown said afterward, but it was hard to tell it by what happened next. He shook free just briefly against Wright, but it was enough. The shot arched in from 25 feet with 14 seconds remaining. With it went the Bullets hopes for their first victory in nine championsip-round games.

"This won't have any effect on what we do from now on," said Wes Unseld, the only Bullet to play in the team's two previous 4-0 shutouts in these best-of-seven title rounds (1971, 1975). "We had a spurt and then they had a spurt and their spurt was good enough to win.

"This makes you think you can get 19 points ahead again. And then you have to hope you don't blow it. We still have to win one here and we've got three more chances. It's that simple."

But Coach Dick Motta admitted that the Sonics "will be in the driver's seat" if they can split the next two games, Thursday and Sunday in Capital Centre.

Grevey was hurt with 3:01 left after being bumped by Brown while putting in a fastbreak layup. "I lost my balance and landed with the full weight on my left ankle," he said.

He stayed in to sink the foul shot that gave Washington a 98-95 lead, but came out moments later. With him went the Bullets' major outside threat.

Washington needed his long-range accuracy because the Sonics had successfully shut off its two major inside scorers, Elvin Hayes and Dandridge.

Dandridge had by far his worst playoff game, scoring six points just two in the second half. In the fourth period he was shut off while Hayes, who had 21 in all, was limited to one basket.

Charles Johnson did his best at the end to make up for this inside void. He sank two long jumpers after Grevey left to keep the Bullets ahead by three, 102-99, but then he missed his last two shots and Wright one to open the door for Brown.

Motta had feared that if the Seattle guards got untracked, the Bullets would happen problems. For a half, Washington controlled Brown & Co., limiting the the Sonic backcourt to 21 points. But in the fourth period, Brown and Dennis Johnson combined for 24 of Seattle's 33 points.

Their shooting the fine performance of small forward John Johnson and the rebounding of Silas were the major ingredients in the Sonics' startling comeback.

John Johnson won his key matchup with Dandridge decisively. He scored 18 points, pulled down 10 rebounds and he repeatedly picked up loose balls during the fourth period.

"I has my shots against him and a lot of them didn't fall," said Dandridge. "He played well, he hustled. Give him credit. But I'll take those same shots the rest of the series and make a lot of them."

Motta complained that the Bullets were complacent after building their 19-point bulge. "We stopped hustling," he said, and pointed to all the second shots and offensive rebounds the Sonics pulled in during the second half as proof.

Led by Marvin Webster and the wily Silas, the Sonics pulled down 19 more rebounds than Washington, including a 21-8 margin on the offensive end.

"We had them out of their offense for three quarters," said Motta. "Then we got only one offensive rebound in the third quarter. Things had come too easy for us. We got lethargic. It was our fault, we had it and we let it get away.

"When you can't get long rebounds, you can't cry about anything. The game was there for us to win."

In the Seattle dressing room, center Webster, who contributed 17 points and 14 rebounds, was saying the same thing.

"It was almost hopeless," he said of the 19-point deficit. "It was almost hopeless."

Almost doesn't count, and the Bullets have three days to think about what they did wrong and as Motta said, "correct enough things to make sure this doesn't happen again.

"At halftime, I couldn't have felt better about how things were going. Then they just pulled the plug on us."