Jarkko Immonen scored his first NHL goal in the opening minute of the second period and Martin Straka snapped a tie in the closing seconds of the frame to help the Rangers stretch their Atlantic Division lead with a 3-1 victory over the Islanders last night.

Straka gave the Rangers a 3-1 lead 8:55 into the third period when he scored his second of the night and 21st of the season. He has seven goals in five games.

The Rangers, 5-1-1 this season against the Islanders, lead Philadelphia by five points with six games left. Philadelphia has seven to play.

The 23-year-old Immonen was recalled to make his NHL debut earlier Thursday, replacing injured center Steve Rucchin, and got the Rangers even 21 seconds into the period. Straka made it 2-1 with 47.6 seconds left.

The goal was met with much fanfare, and that had nothing to do with Straka. Originally, Jaromir Jagr – the NHL leader in goals and points – was announced as the scorer, which would have given him a team-record 53rd of the season.

Chants of “M-V-P” rained down throughout Madison Square Garden, and Rangers coach Tom Renney even called Jagr back to the bench so fans could salute him again. But when the buzzer sounded to end the period moments later, Jagr skated over to the referee to apparently tell him that he never touched the puck.

Before the start of the third period, an announcement was made that the goal was Straka’s and drew groans and a few boos. Straka’s pass into the slot struck the skate of Islanders forward Wyatt Smith – not Jagr – and deflected in behind goalie Rick DiPietro.

Jagr has no goals in four games.

That restored a bit of normalcy for the Rangers, who bounced back from a lackluster opening period.

For the first time since 1997, the Rangers took the ice as a team heading to the playoffs and came out flat. After locking up a spot Tuesday with a shootout victory over Philadelphia, the Rangers looked a bit uninspired even against their biggest rival.

But the challenge wasn’t quite the same as the Islanders played their first meaningless game of the season. They were eliminated from the postseason – after three straight appearances – when they lost in Toronto on Wednesday.

Rangers fans reminded them off their plight by chanting “Season’s Over!” as the final minutes ticked down.

Despite having three power-play chances in the first period, two on penalties to DiPietro, the Rangers managed just five shots and handed the Islanders their only goal.

Tom Poti, whose end-to-end rush and cross-ice pass set up Straka’s second goal, made a bad clear from his zone that was picked off by Miroslav Satan in the neutral zone. The Islanders’ leading scorer, who netted his 30th of the season Wednesday night, carried the puck into the Rangers’ end and beat Kevin Weekes with a long shot from above the left circle at 10:39.

Weekes looked sharp in turning aside a few good scoring chances early and finished with 21 saves. He earned his second straight home win – after not winning there since November – in place of injured starter Henrik Lundqvist, who is day to day with a sore hip.

Weekes has won consecutive games four times this season. Twice he won three in a row.