Penguins 5, Senators 2 .

PITTSBURGH — Sidney Crosby and Mark Letestu scored power-play goals in the first period and the Penguins won their third in a row, ruining defenceman Sergei Gonchar's return to Pittsburgh by beating the slow-starting Ottawa Senators 5-2 on Monday night.

Evgeni Malkin also scored as the Penguins won their fourth in five games since losing three of four. All three of those losses were in the new Consol Energy Center, where the Penguins have since won their past two.

Letestu, a rookie with only one goal in 10 NHL games entering this season, has four goals to match Crosby for the team lead and has three assists. It's early, but he's giving the Penguins the supplement scoring they badly need from someone other than former NHL scoring champions Crosby and Malkin.

Crosby, Malkin and Letestu each had a goal and an assist. Mike Comrie had two assists.

Penguins backup goalie Brent Johnson, making his third consecutive start, turned aside 32 shots and now is 4-0-0. Marc-Andre Fleury, who last started in Pittsburgh's 4-3 loss at home to Toronto on Wednesday, is 0-3.

Johnson's best stop came when he poked the puck off Mike Fisher's stick as the Senators centre neared the net on a breakaway with the Penguins up 5-2 midway through the third period.

Gonchar, the power-play anchor of the Penguins' Stanley Cup finalist teams in 2008 and 2009, was on the ice for every goal in the first two periods as Pittsburgh took a 5-1 lead. An exasperated coach Cory Clouston benched goalie Brian Elliott after he stopped only 17-of-22 shots, with Robin Lehner playing the rest of the way.

Ottawa, a first-round playoff loser to Pittsburgh last season, is 1-4-1 — partly because of a power play that is only 2-of-24. That includes captain Daniel Alfredsson's goal at 5:40 of the second period, his first this season.

"I don't think anybody is happy," Gonchar said. "We're all frustrated. But it's one of those things that you have to battle through. You have to stay positive."

Pascal Dupuis and Kris Letang responded to Alfredsson's goal later in the second period with goals 25 seconds apart to make it 5-1.

"If we're playing how we can, I really like this team," Alfredsson said. "Right now, we're just not getting the most out of everybody ... We're one step behind at times."

Gonchar and Alfredsson pointed to Pittsburgh's two early power-play goals as the difference.

Letestu, who scored the game-winner in two of Pittsburgh's first three victories, took advantage of a too many men on the ice penalty to put a knuckleball-like shot under the crossbar at 8:39 of the first.

Crosby scored his third goal in two games when Alex Goligoski's shot went wide and deflected to him at the side of the net.

Slightly more than three minutes later, Letestu won a faceoff in the Ottawa zone and the puck banked off Comrie to Malkin in front for a 3-0 lead.

NOTES: Crosby had five goals and nine assists in Pittsburgh's six-game playoff series win against the Senators last spring. He previously had only two regular-season goals in 17 games against them ... Ottawa has been outscored 17-8 while going 0-3-1 on the road ... Alfredsson's goal was his 997th career NHL point ... The Senators next see action Friday in Buffalo against the Sabres (7:30 p.m., Sportsnet East, Team 1200).