James Neal scored twice and Sidney Crosby had a goal and two assists to help the Pittsburgh Penguins beat Ottawa 4-2 on Wednesday night in a game marred by the loss of Senators star defenceman Erik Karlsson to a left Achilles injury.

The Norris Trophy winner last season as the NHL's top defenceman, Karlsson was cut by Penguins forward Matt Cooke's skate blade as the two tangled along the boards late in the second period. The Senators said Karlsson will need surgery.

Pascal Dupuis also scored for Pittsburgh, Paul Martin had two assists, and Marc-Andre Fleury made 26 saves. The Penguins snapped a two-game losing streak to pull within a point of Eastern Conference-leading New Jersey.

Stephane Da Costa scored his first goal of the season, and Jim O'Brien also scored for Ottawa. The Senators lost for the fifth time in seven games.

The loss of the Karlsson is a major blow for the Senators, already playing without centre Jason Spezza and left wing Milan Michalek. Spezza is out indefinitely after surgery for a herniated disk, and Michalek was a late scratch Wednesday because of a lower-body injury.

Ottawa, behind Craig Anderson's 42-save effort, shut out Buffalo on Tuesday night at home, but couldn't carry the momentum to Pittsburgh. Anderson stopped 25 shots Wednesday.

Penguins defenceman Kris Letang returned after missing three games because of a groin injury. He was paired with Matt Niskanen, who also returned after missing eight games with an ankle injury.

Both goalies were strong early as the teams combined for 26 first-period shots. The Penguins scored the lone goal of the opening period, the 11th time in 14 games Pittsburgh scored first.

Dupuis one-timed his fifth of the season behind Anderson with 3:37 left in the period, taking a cross-ice feed from Crosby, who set up the goal after pouncing on Chris Neil's turnover at the blue line.

The Senators took the lead with goals scored 24 seconds apart.

The first came just as a two-man advantage expired as Da Costa, from behind the net, banked a shot off the back of Fleury's pads that trickled across the goal line.

O'Brien gave the Senators the lead 24 seconds later with a wrist shot from the faceoff dot that caromed off Fleury's glove and bounced into the net.

Neal tied it less than 3 minutes later with his NHL-leading sixth power-play goal, the sixth straight game the Penguins scored with the man advantage. Crosby recorded his 400th career assist on the goal, sending a pass from the corner to Neal, who unleashed a wrist shot over Anderson's shoulder from the faceoff dot.

Neal gave the Penguins the lead for good 1:52 into the third period, tapping the rebound from Deryk Engelland's shot from the point past a sprawled Anderson. Crosby's sixth of the season, coming seconds after a Senators' penalty expired, put the Penguins ahead by two goals midway through the third.