Alex Kovalev broke a lengthy scoring slump with a career-best four goals and an assist to lift the Ottawa Senators to a 7-4 victory over the Philadelphia Flyers in the NHL Sunday. The Senators jumped out to a 4-1 lead before squandering it, then ran away with three third-period goals. Kovalev scored his first goals in 11 games, dating to a hat trick on Dec. 12 against Carolina. It was his 12th NHL hat trick. His first goal came against Flyers starter Michael Leighton, who was replaced by Brian Boucher after giving up two goals on five shots. Ottawa's Pascal Leclaire allowed three goals on 10 shots before being relieved by Brian Elliott. Chris Kelly had his first career two-goal game for the Senators, who won for the fourth time in five games. Jarkko Ruutu added a goal and an assist, and Ryan Shannon and Anton Volchenkov had three assists each. Arron Asham had a goal and assist, and Ian Laperriere Darroll Powe and Mike Richards scored on the power play for the Flyers. Sabres 1, Canadiens 0: At Montreal, Ryan Miller posted his fifth shutout of the season and Tim Connolly scored the lone goal as Buffalo beat Montreal to extend its winning streak to four. Miller turned aside 30 shots - including Mike Cammalleri's one-timer with just over 12 seconds remaining - for his second straight win since being chosen for the U.S. Olympic team on Friday. It was his 17th shutout in 299 NHL regular-season games. Connolly scored his fourth goal in four games in the second period for Buffalo, which has won 14 of 20 (14-4-2) since Nov. 27. Carey Price made 29 saves for Montreal. Panthers 6, Penguins 2: At Sunrise, Florida, Radek Dvorak scored three goals for his third NHL hat trick and Tomas Vokoun stopped 46 shots as Florida sent Stanley Cup champion Pittsburgh to its season-high, fifth straight loss. Rostislav Olesz, Jordan Leopold and Steven Reinprecht also scored for the Panthers, who rallied from a 2-0 deficit and snapped a three-game losing streak. Nathan Horton, Michael Frolik and Gregory Campbell each had two assists. Sidney Crosby and Tyler Kennedy scored first-period goals, and Marc-Andre Fleury made 29 saves for Pittsburgh, which has lost six of seven.