"You can't intimidate either of these clubs at home," Boston defenseman Brad Park said after the New York Islanders had showed that to be true in beating the Bruins here, 7-3, Saturday night for a 2-1 games lead in their best-of-seven Stanley Cup semifinal series.

The next game will be in Nassau Coliseum Tuesday night.

On Thursday, the defending champion Islanders had been stymied in a 4-1 loss at Boston. The Islanders had plenty of scoring opportunities but could not convert them into goals.

"We knew what the problem was at the time, and you just get to pressing, which doesn't make it work any better," said Denis Potvin, who scored the lone goal Thursday. "You can talk about things all year long, but until you start to do them, it's no good. Tonight (Saturday) we did things right."

Most of what went right was the Islanders' power play. Noticeably ineffectual in Game 2, the man-advantage unit went three for four, including a late-game score by Potvin.

"These are all things we're supposed to be capable of doing very well, and it can get to you a little when they don't happen," Potvin said.

Winger Mike Bossy, one of the National Hockey League's premier scorers in such situations, had a power play goal of his own and three assists. "What was the difference in the power play here?" he said, repeating a question. "The pucks just went in. We concentrated on that area, and the pucks went in."

The Islanders also wanted to avoid more short-handed goals by the opposition. In Thursday's game, the Bruins had two. There was little chance for that Saturday night because Boston, playing end-to-end hockey and attempting to catch up with the Islanders from the first period on, had trouble generating an attack with all of its skaters.

"We took penalties tonight, and we just weren't killing them off," said Coach Gerry Cheevers. "It was frustrating to see."

Cheevers did not blame the play of goalie Pete Peeters, who stopped 19 shots, for the loss. But Peeters, who has played like a playoff goaltender all season long, more closely resembled the Pete Peeters that Philadelphia fans recall, a goalie who could be awful on too many occasions. His wandering style too often deteriorated into diving flops.

"I think maybe we did expect to see a different game from him," Bossy said. "We might see it Tuesday."

New York defenseman Stefan Persson, who wrenched a knee in the opening game of the series, has been skating, but Coach Al Arbour is unsure whether he will return to the lineup Tuesday . . . Pleased with the Game 3 performance, Arbour made today's afternoon practice optional. As the word went around, none of the Islanders seemed to believe it. "You know we'll all be out there," said Bob Nystrom.