NEW YORK - It’s a fine line the Rangers are walking.

When they adhere to the plan, everything happens to fall into place.

When they don’t, disaster strikes.

Last night, the Blueshirts decided to move away from their ‘defense first’ play that netted them 9 out of 10 wins and freelanced a little bit. The result was a 2-1 Islander win at Madison Square Garden.

“[The Islanders] played a smart road game,” said Brendan Shanahan, who setup Michal Rozsival for the Rangers goal, shorthanded. “We allowed them to frustrate us and we got away from our structure that has been successful and we kind of got on our own. When that happens, five guys on the same page will make you look stupid.”

With goals coming from Ruslan Fedotenko and Josef Vasicek less than six minutes into the second, the Rangers were unable to respond in kind. Yes, Rozsival’s goal with Blair Betts in the box, was impressive, but the Blueshirts could not set up their own power play – going 0-4 - and weren’t able to get the shots on Rick DiPietro [18 saves] who netted his 100th career win.

“It looked like we are chasing the puck around a lot, which is how it looked for us,” Shanahan continued. “The desire was there, but the brains were not. We allowed frustration to alter our game. I don’t know if we want to beat them so badly or what it is but we have to settle down and trust the system that worked so far.”

Whatever it is, the Islanders do have the Rangers number this season, giving the Blueshirts three of their eight losses with two coming during this hot streak over the past 11 matches, when the Rangers won all the other contests.

“The Islanders managed their game well,” said coach Tom Renney. “They made choices with the puck that put us in a situation making us try too much. They just worked hard. They got pucks in behind us and clogged up the neutral zone. Consequently, we tried to do too much ourselves. We didn’t share the workload, like we have been.”

Added Sean Avery: “We tried to get too individual in our game. As a team we have to play a team concept, when we get away from it and play too much as an individual, it’s not going to work.”

And although Henrik Lundqvist was solid in goal with 22 saves, he could not save the day for the Blueshirts.

“It's weird. We don't really get it,” Lundqvist said. “They've been good. They play smart.”

The play on the ice – especially in the second period – was very aggressive with five roughing penalties called during the game, including one on DiPietro after he proceeded to pounce on Sean Avery when Fedotenko pushed the Ranger forward into the goaltender.

Equally as rough was the mostly partial Ranger crowd as fights broke out between fans throughout the game.

Which is what the rivalry needs, but it also needs both teams playing at the top of their games. Last night, though, only the Isles were up to the task and they came out the winner.

Notes: Dating back to last season, the Islander hold a 7-4-1 record on the Rangers with a 4-1 mark at the Garden…Rozsival’s goal was his seventh of the season. Last year he set his career high of 10…The Rangers go on the road for matches in Tampa Bay and Florida on Wednesday and Friday, respectively. They return home for a 1 p.m. game on Sunday against Dallas.