UNIONDALE, N.Y. -- The Ottawa Senators suddenly went from slumping to sizzling.
The head start is over, and now the Senators are taking aim on the Eastern Conference.
Dany Heatley scored twice, Jason Spezza had three points, and Martin Gerber won the battle of backup goalies to lead the Senators to another victory over the New York Islanders, 4-2 Tuesday night.
Even with Gerber getting the start over No. 1 goalie Ray Emery, the Senators didn't slow down. They won their fourth straight and for the eighth time in nine outings. That 6-10-1 opening is a thing of the past, and the Senators (15-12-1) are now above the playoff cut line in the East.
"Right now we're playing pretty good hockey," said captain Daniel Alfredsson, forced out in the third period with a leg injury. "We've found our game and everybody is working really hard. When we do that, we're a tough team to play against."
Spezza set up Heatley's first-period goal and defenseman Joe Corvo's man-advantage tally in the second restored Ottawa's two-goal lead. Spezza netted his 13th goal late in the middle frame to make it 2-0 and send the Senators on the way to their fifth straight win over the Islanders.
Heatley added his 18th goal with 7:50 left to make it 4-2.
"We just weren't playing well early on as a group," Heatley said of the slow start. "Once we got in a hole we realized we've got to get going."
Ottawa improved to 27-4 with eight ties against the Islanders since Feb. 12, 1996. The Senators also prevented New York from extending its slim edge in the Atlantic Division.
The Islanders are on top of New Jersey and the New York Rangers by one point and haven't owned a bigger advantage in the division since they had a two-point lead on Feb. 18, 1990.
New York fell to 2-3 without injured captain Alexei Yashin, sidelined with a knee injury. There appeared to be a hangover from a 7-4 road win Sunday over the Rangers.
"We didn't start well at all," forward Mike Sillinger said. "Any time we got within one goal, we just didn't have enough juice.
"If we want to stay on top of our division, we have to fight our way through this."
Mike Dunham, getting the start in place of regular goalie Rick DiPietro, fought the puck throughout and gave up big rebounds. He kept the Islanders in it early when Ottawa held a 17-4 shots advantage through the first period and finished with 31 saves.
Andy Hilbert's first goal of the season brought the Islanders within 2-1 at 9:38 of the second period but Alfredsson found Corvo cutting to the net and hit him with a backdoor pass that was steered in at the right post with 49.4 seconds left in the frame -- eight ticks into Ottawa's third power play.
Jason Blake made it 3-2 at 6:42 of the third, doing the grunt work to set up the goal, too. Blake checked Anton Volchenkov hard into the boards, forcing a turnover and leaving the Ottawa forward with an injured arm. The puck went behind the net to Bruno Gervais, who made a quick pass in front to Blake, who scored his 15th goal.
Volchenkov was back for his next shift, but captain Alfredsson didn't return after absorbing a check by Tom Poti behind the Islanders net four minutes into the third. He struggled to get to the bench and then gingerly skated to the dressing room after the next whistle.
"I just tweaked the muscle a little bit," Alfredsson said. "It feels better now and we'll see how it goes tomorrow."
Gerber was sharp despite seeing little action through the first half of the game, and made 24 saves. He even turned aside Viktor Kozlov, who scored six goals in two games - including a four-goal effort Sunday.
Emery has gotten the bulk of recent work, going 7-2 while starting nine of the previous 10 games. Gerber won his second straight, both in the past week.
"I don't want him to sit forever," Senators coach Bryan Murray said. "He struggled early as our team did but it looks like he's got it back."
Spezza played a strong game, setting up Heatley's team-leading 17th just 4:32 in and ripping in a hard shot from the top of the left circle with 1:33 left in the period.
This is the latest the Islanders have owned sole possession of first place since Dec. 14, 2001. ... Hilbert's previous goal was 26 games earlier on April 17 for Pittsburgh against the Islanders. ... DiPietro sat out with an undisclosed injury but is expected to play Thursday against Montreal. ... The Senators, 4-0 against the Islanders last season, have outscored opponents 38-18 the past nine games.