For one night, at least, they were the Islanders of old. Veterans Bryan Trottier, Denis Potvin and Mike Bossy were among the goal scorers tonight as New York defeated the Philadelphia Flyers, 6-2, and stayed alive in the pursuit of the Stanley Cup.

In the process, the Islanders chased Flyers goalie Pelle Lindbergh, who had been so outstanding as Philadelphia sent the Islanders to the brink of elimination with three straight victories. This time Lindbergh yielded four goals in 12 shots and was replaced by Bob Froese.

This is the Islanders' 34th playoff series, of which they have won 27, and they maintained a proud record of never being swept. To do it, they snapped the Flyers' 11-game winning streak and ended a string of six losses at Philadelphia's hands.

Kelly Hrudey stopped 24 shots in earning his first playoff victory for the Islanders, who visit the Spectrum Sunday hopeful of pulling off yet another miracle. Only the 1975 Islanders and 1942 Toronto Maple Leafs won a seven-game series after dropping the first three games.

"Our backs were to the wall and we had to win," said Islanders Coach Al Arbour. "We finally broke Pelle Lindbergh -- he'd been fantastic in all the games. Hopefully, we can throw him off balance and keep him off balance like that."

In addition to scoring six times, three on power plays, the Islanders hit four posts and were in the Philadelphia end most of the night. Despite the lopsided score, though, there were two big plays that stood out.

After Pat LaFontaine and Trottier had lifted New York into a 2-0 lead in the first eight minutes, Islander Alan Kerr was assessed a double minor, for tripping Lindsay Carson and responding to a post-whistle bump by Ed Hospodar with a cross check in the back.

Hrudey made four saves during the four minutes, including a stand-up block when Brian Propp sailed in at the finish of a two-on-one with Tim Kerr. It was the kind of stop Billy Smith had not been able to make in the previous two games.

"No doubt about it, we needed a big save at the right time," Arbour said. "We had it throughout the playoffs against Washington, but we hadn't been doing it in this series. In the other games, we'd be forcing the play and then they'd come back and score."

It was still 2-0 early in the second period, when Flyer Todd Bergen fed Tim Kerr at the left post and Kerr fanned. It was the kind of shot that had been automatic for Kerr all season.When the Islanders regained possession, they moved the puck quickly to the other end. Bossy drew two Flyers toward him along the left-wing boards, then spun and fed the unguarded Potvin in the slot. He beat Lindbergh with his 53rd playoff goal and, instead of 2-1, it was 3-0. For all purposes, it was also over.

Bossy took Stefan Persson's pass in the slot and beat Lindbergh at 8:53 of the period, tying Maurice Richard's career playoff record of 82 goals and prompting Philadelphia Coach Mike Keenan to replace Lindbergh with Froese.

Bossy left the game in the third period and was gone when the dressing room was opened afterward. Arbour said that Bossy "got caught in a rut and fell on his back. He's all right, but we didn't want to take any chances."

Derrick Smith ended Hrudey's shutout bid two minutes later, then the teams fought through a ragged third period in which New York scored two power-play goals to the Flyers' one -- Tim Kerr's eighth of the playoffs.

Philadelphia's Joe Paterson was ejected for attacking Bob Nystrom after the officials finally had broken up a lengthy brawl ignited by Potvin and Ron Sutter. Flyer Dave Brown also was bounced with a misconduct after he attacked Duane Sutter.

Arbour declined to say whether Hrudey would start in goal on Sunday, saying, "It's still day to day. We'll just go a minute at a time." But it seems unlikely that he will return to Smith, who is winless at the Spectrum since 1980.

"I was just glad we won and I was able to help," Hrudey said. "Al came into the room before the game and told us to give it all we had on every shift. That's what we did. We took it one shift at a time and we didn't look ahead."

Keenan boycotted the postgame press conference, as Arbour did Tuesday. So it was left for team captain Brad Marsh to express the Flyers' view of the game: "We played a bad game and they played a good game. We need the whole team going. Maybe four or five guys weren't going all out when we got behind three or four goals."