Tampa Bay, 29th among 30 teams in penalties, spent much of the period killing them. The Islanders got the first break at 2:15, when a hooking penalty on Martin St. Louis gave New York a man advantage and removed the Lightning's best player from the ice.
Tampa Bay's penalty kill did the job as Fredrik Modin and Dave Andreychuk made clearing plays and New York was held without a shot.
The Lightning got a power play of its own when the Islanders were whistled for too many men on the ice at 4:26. But it managed only one shot on goal.
The Islanders had better scoring chances moments after their second power play, but Nikolai Khabibulin stopped three shots from in close.
Ruslan Fedotenko was penalized for tripping at 10:28, giving New York a third power play. An apparent equalizer went uncalled 38 seconds later, when Kenny Jonsson appeared to catch Pavel Kubina with a high stick, cutting Kubina's face.
THE POSITIVE: The Lightning limited the Islanders to six shots despite having to kill three penalties.
THE NEGATIVE: Tampa Bay spent most of the period playing defense and managed only five shots.
KEY PLAY: An apparent breakaway goal by St. Louis was waved off at 12:35. Replays showed the puck bounced off the top right corner where the post meets the crossbar.
KEY PLAYER: Besides drawing the St. Louis penalty and cutting Kubina, Jonsson broke up a two-on-one with St. Louis and Vinny Lecavalier with two minutes left.
Second period: Turnovers lead to goals
After a lengthy delay to replace the scoreboard phone, the Lightning entered with 1:50 of power-play time. But the advantage lasted only 22 seconds before Brad Richards was sent off for holding a stick.
A tremendous effort by fourth-line wing Andre Roy put the Lightning ahead at 5:07. Roy was on the ice less than a minute before he intercepted the pass of defenseman Eric Cairns at the blue line, skated into the slot and scored into the upper-left corner.
A second Cairns gaffe led to another Lightning goal at 11:06. After skating behind the Islanders net, Cairns was stripped of the puck by Fredrik Modin, whose backhander from the top of the crease beat Rick DiPietro stick side.
The Islanders got their fifth power play when St. Louis was penalized for hooking at 16:51. But a second too many men on the ice infraction ended the advantage after 1:09.
THE POSITIVE: The Lightning took advantage of two giveaways to take a two-goal lead.
THE NEGATIVE: New York outplayed Tampa Bay for much of the period and held a 15-5 shot advantage.
KEY PLAY: With Nikolai Khabibulin out of the play, Lightning defenseman Dan Boyle slid into the crease to block Michael Peca's shot into what would have been an empty net at 8:00.
KEY PLAYER: Khabibulin was phenomenal, stopping Oleg Kvasha from in close then falling on Adrian Aucoin's rebound attempt, which had trickled behind him, early and later stoning Dave Scatchard and Mark Parrish from point-blank range.
Third period: Modin puts it away
The Lightning's unheralded fourth line nearly had a second goal when Andre Roy passed across the slot to a wide-open Chris Dingman. But Rick DiPietro stacked his pads to make the save at 2:55.
Tampa Bay had another great chance at 5:37, but Martin St. Louis fanned on a shot from the slot as DiPietro tried to recover after getting tied up behind the net.
An apparent Islanders breakaway turned into a Lightning power play when Mattias Weinhandl was penalized for hooking Cory Stillman at 9:24.
Modin made New York pay 1:35 later, tipping Darryl Sydor's shot from the top of the left circle past DiPietro to seal the victory.
THE POSITIVE: The Lightning stayed out of the penalty box, even when Steve Webb tried to bait Roy, and scored the only power-play goal to put the game away.
THE NEGATIVE: With the exception of the first few minutes of the game, the Lightning largely was unable to establish any kind of a forecheck.
KEY PLAY: With plenty of time remaining for New York to get back into the game, Nikolai Khabibulin twice stopped Weinhandl from the lower left circle in the opening minute.
KEY PLAYER: Modin used his hands to deflect Sydor's shot past DiPietro. However, his positioning directly in front of the Islanders goal obscured DiPietro's view of the shot and made the deflection possible.