Never in National Hockey League history has a team lost the first two games of a best-of-five playoff series and come back to win. The New York Islanders think they can become the first.

The Islanders beat the Washington Capitals, 2-1, tonight on third-period goals by Bryan Trottier and Brent Sutter, forcing a fourth game here Sunday at 7 p.m. in their Patrick Division semifinal.

Unlike the first two games, this one was settled in the regulation 60 minutes. But from start to finish, it was played like overtime, with both teams seemingly afraid to make a mistake.

All the thrills for Washington fans were confined to the last 1 1/2 minutes, after goaltender Al Jensen had been lifted for a sixth skater with New York ahead, 2-0.

Trottier was headed in for the clincher, only to find defenseman Scott Stevens filling Jensen's role. After a brief head fake, Trottier fired away and Stevens went down, goalie fashion, to block it.

Bengt Gustafsson quickly sent the puck ahead to Dave Christian, who was tied up by two Islanders and shoved past the goalline.

Nevertheless, Christian managed to slide the puck out of the tangle to Mike Gartner in front, and he trimmed the deficit to 2-1 with 41 seconds left.

"I just backed up and waited for him," Stevens said. "He deked and I guessed. I just guessed right. When we came back and got the goal right away, I thought it might be a big play."

The Islanders had three shots at the empty net from long range and all missed. After the last one, the Capitals carried the puck into the Islanders' zone and Stevens' pass to Gartner barely missed connections in front, with the puck caroming off Gartner's stick into the corner.

"It just slid by my stick," Gartner said. "I just missed getting it."

"We had a chance," Stevens said. "I really thought Garts was going to get it. It was that close."

The Capitals came close earlier in the period, as Bob Carpenter barely failed to control a pass from Gartner in front of goalie Bill Smith. Almost as fast as a disappointed Washington fan could say 'Aw shucks,' the Islanders had the first goal of the game.

As the Capitals tried to set up once again in the New York end, Rod Langway slid a pass from the left point toward Mike McEwen on his right. Mike Bossy got his stick in the way and deflected it to Bob Bourne, who sent a headman pass to Trottier.

With Bossy on his right wing and Langway drifting back, Trottier fired from the left wing circle and beat Jensen high on the short side at 5:11.

At that point, Washington had 12 shots, New York 11.

"I knew Boss was over there, but he held up at the blueline and I thought Jensen was kind of cheating to Boss, so I shot it," Trottier said. "You don't think, you just react."

Asked if he had a feeling of relief that the Islanders had gone ahead at last, Trottier said, "I don't remember feeling relieved. I didn't think anything. I just kept playing until it was over. Now we're still in it. When June comes around and we've won it, then I'll sit back and think about how I felt along the way."

If Trottier noticed no relief, Brent Sutter did. Then he felt even better, when his goal boosted New York's lead to 2-0 at 13:44.

Sore-kneed Dave Langevin, who made his series debut in place of ailing Tomas Jonsson, blocked a shot from the right point by Mikko Leinonen. John Tonelli pounced on the deflected puck and passed to Duane Sutter, who relayed it to brother Brent.

Again the man on the left side of the two-on-one elected to shoot rather than pass. Brent ignored his sibling and lined the puck into the far corner.

"As soon as he gave it to me, I had it in my mind to shoot," Brent said. "I just tried to shoot as hard as I could and get it on net. I knew Duane was there for the rebound.

"It doesn't matter who scores in the playoffs. They're playing a close-checking game and so are we and whatever breaks come, we have to take advantage of them. We got a break when Trots scored and we got a break when I scored.

"I was very confident tonight. I knew if we gave it a great effort, we'd be all right. Our backs were to the wall and we knew we had to come up big."

The capacity crowd of 16,002 was beginning to wonder, however, and there were some boos during an unsuccessful New York power play in the second period. Incredibly, the Islanders managed only four shots in the first 36 minutes.

They had a fifth -- and it went in, but it did not count. Midway through the second period, Stefan Persson beat Jensen with a drive from the top of the left wing circle. However, the whistle blew a moment before he shot, as Bossy was knocked offside on the right wing.

"I was tripped and I couldn't stay onside," Bossy said.

Bossy was frustrated much of the night by Gaetan Duchesne, although Coach Al Arbour tried to shift Bossy to different lines to free him.

Duchesne continually jumped off the bench in quick changes on the fly to stay with him.

The Islanders did find a way to get Duchesne off Bossy's back for a while in the second period. As Duchesne touched the puck to stop play during a delayed penalty to Stevens, Bourne took a run at him with both gloved hands balled into fists. Duchesne was knocked cold and missed several shifts while the bells stopped ringing.

"I run into that kind of checking a lot during the regular season," Bossy said. "In the playoffs things are even more intense and they become very defensive. When you have that kind of game played against you, you change your style. If you don't get any chances, you make sure they don't get any, either."

There were more penalties (11) than shots (eight, two by New York) in the first period. Included in the varied sentences were majors to Duane Sutter and Washington's Greg Adams, for a brief scuffle in which Adams threw Sutter to the ice and lay on top of him, while Sutter pulled Adams' helmet apart in a vain attempt to bare his head.

Langevin delivered some heavy hits, with McEwen and Alan Haworth taking their lumps after skating in his direction.

"There are things I can do -- punish them, move the puck and block shots," Langevin said. "They know me by now -- it's that kind of series. They have to keep their heads up. Before it was over, they were looking at me. When I hit Haworth coming through the middle, he looked up and I just smiled.

"That's just one game, though. I can't be happy with one. Will I play tomorrow? I don't know. I was ready a long time ago, and I was disappointed not to play. I knew I could contribute."

Asked about the Islanders' chances to win the series, captain Denis Potvin said, "You just keep going and figure things will turn.

"Things have to turn. We're not out of this by any means. This club has done a lot of things nobody thought we could."