Long after the Islanders had eliminated the Buffalo Sabres Saturday night to advance to the Stanley Cup final, hundreds of New York fans stood outside the players' entrance at Nassau Coliseum chanting "We want Philly."

A replica of the Cup was waved high, while autograph seekers pursued departing heroes. For Islander fans, humiliated by last season's semifinal loss to the hated Rangers, this first-ever trip to the final series should be memorable.

"This was worse than a concert," a sweaty policeman told a colleague. "We had to break up three fights in the corridor. These people are nuts."

"You think this was bad," the other policeman said. "Just wait till next week."

A confrontation between the Islanders and Flyers, two physical teams with respect but no love for each other, promises continuous action, both on and off the ice.

Saturday night, Islander fans screamed loudly throughout the National Anthem, refusing to halt their welcome-home greeting to the team just because officials decided it was time for poor Joe Duerr to try to sing the Anthem.

They roared enthusiastically, with frequent shouts of "Kill him," during several incidents that threatened to turn the game into a war. If this had been the Flyers, they might still be fighting.

Consider this third-period scenario. Buffalo's Lindy Ruff, after being hacked by goalie Bill Smith and defenseman Bob Lorimer while trying to screen Smith on a power play, turned up ice as the Sabres lost possession. Smith drove the butt end of his stick into Ruff's left eye.

Ruff fell, then rose and fired his gloves and helmet to the ice before charging into Smith. Referee Andy Van Hellemond went down in the melee, which was quickly terminated mostly because Ruff's contact lens had been pushed off the eyeball and he was too fearful of serious eye injury to prolong things. But suppose Ruff had been the Flyers' Bobby Clarke.

Clarke was punched, very lightly by Minnesota's Rob Flockhart during the Flyers' concluding victory Thursday. Immediately, Philadelphia's Paul Holmgren circled the officials and started pounding Flockhart.

There were other incidents Saturday. The Islanders' John Tonelli was taken into the boards by Buffalo's Jim Schoenfeld and retaliated with a high stick. Schoenfeld, trying to fight back, was hauled down in a stranglehold by Islander Duane Sutter. Suppose that was big Dailey nursing the sore throat.

Another time, Buffalo's Richard Martin and the Islanders' Stefan Person swung sticks at each other. As they were separated, Schenfeld and New York's Bryan Trottier exchanged two-fisted greetings to each other's face. Suppose that had been Moose Dupont instead of Schoenfeld

The supposing will become reality Tuesday night, when the teams open the best-of-seven final series in Philadelphia. It certainly will be the most physical final since Boston-Philadelphia in 1974, the Montreal Canadiens having provided a civilizing influence in most of the years since.

"We know what the flyers are like and they know what we're like," said Islander Bob Bourne. "We're a different team from Minnesota."

What Bourne means is that the Flyers' clever jabs with stick and elbow will be returned in kind. The North Stars put up with the Flyers' constant abuse because they knew they had no chance to win if they tried to change to a hacking, heckling style.

There will be another contest in Philadelphia, on Thursday, before the Nassau Coliseum police contingent gets its first workout on Saturday. Game four will be played here Monday, May 19, a day ahead of schedule because Canadian television will be occupied with the Quebec secession referendum the following day. The remainder of the schedule has not been finalized; but the Flyers, by finishing first during the regular season, own the rights to game five and seven.

Certainly the referees have been thinking about it. If Van Hellemond, the NHL'S best, was barely able to keep the Islanders and Sabres under control, what are the hopes for law and order in the upcoming battle of the behemoths? Stay tuned, and be prepared to be turned very late each evening.