Philadelphia, PA (Sports Network) - Danny Briere's power-play goal with 3:38 remaining in regulation proved to be the game-winner, as the Philadelphia Flyers doubled up the Montreal Canadiens, 4-2, in Game 4 of their Eastern Conference semifinal series from the Wachovia Center.

R.J. Umberger scored twice for the sixth-seeded Flyers, who hold a 3-1 lead in the series and are one win away from reaching the conference finals for the first time since 2004, when they were ousted in seven games by the eventual Stanley Cup champion Tampa Bay Lightning.

Scott Hartnell also lit the lamp and Briere added an assist, while Vinny Prospal collected two helpers. Martin Biron was a rock in goal, stopping 36 of 38 shots to earn the victory.

"We can't expect it to be easy," Umberger said. "I think we learned that the first series. They're going to fight for their lives. Their backs are against the wall and they're going to come out hard. We might have eased up on our last time, 3-1 against Washington. You have to have that killer instinct this time of the year."

Forward Mike Knuble returned to the lineup for the Flyers and notched an assist. Knuble slid awkwardly while trying to block a shot late in the second period in Game 5 of the team's conference quarterfinal series against the Washington Capitals and suffered a torn hamstring. He missed the final two games of that series and the first three games of the current set.

Tomas Plekanec and Saku Koivu provided the offense for the top-seeded Canadiens, who will host Game 5 on Saturday. Francis Bouillon had two assists for Montreal, which has overcome a 3-1 series deficit only once in its storied history. The Canadiens rallied to eliminate the Boston Bruins in the conference quarterfinals in 2004.

Montreal elected to start goaltender Jaroslav Halak and sit rookie phenom Carey Price. Halak, making his first start since March 29 and first of his playoff career, made 22 saves in defeat.

"You have to give him credit, he was good, obviously not good enough," Montreal coach Guy Carbonneau said of Halak. "He was in a tough situation and he made some great saves early."

Hartnell provided some much-needed insurance 6:47 into the third period. Shortly after a Montreal power play had expired, a Canadiens player blindly threw the puck in the neutral zone, where it intercepted by Prospal, who fired a wrister that careened off the far post right to the stick of a charging Hartnell, who jammed home the rebound to give the Flyers a 2-0 lead.

However, the Flyers watched their advantage vanish in a span of 37 seconds.

The Canadiens finally broke through with 7:01 remaining in the third. Josh Gorges' wrister from the right point appeared to deflect off the right skate of Flyers defenseman Derian Hatcher, then the stick of Plekanec and between the pads of Biron.

Off a broken play, Koivu tied the game with 6:24 to play. Mark Streit's blast from the point was stopped in front by Flyers rearguard Randy Jones and fell right to the stick of the Canadiens captain, perched at the right side of the net, and he wasted little time depositing the puck in the back of the cage.

A senseless hit by Montreal forward Steve Begin resulted in an interference penalty. Begin drilled Sami Kapanen into the boards along the Canadien bench while the door was open and Briere connected on the power play to put the Flyers back on top. Prospal's shot from the left circle pinballed off bodies in front right to Briere, who buried the puck past Halak with 3:38 remaining.

Umberger added an empty-net marker in the dying seconds to seal the win.

"Biron has been on top of his game, whether he's lucky or extremely good, he's making the saves and that's part of the hockey game," Carbonneau said. "We've been able to pierce him in the third period, but we have to find a way to do it in the first and second period early so we can get that confidence back."

Biron's tremendous play between the pipes was the story of the first period, as the 30-year-old netminder stopped all 14 shots the Canadiens fired in his direction.

At the other end, Halak made seven saves in the frame, none bigger than a save on Jeff Carter while the Canadiens were on the power play at the 5:56 mark. Carter positioned himself in the shooting lane, blocked Streit's shot from the point and skated in alone on the Montreal goaltender. Carter went to backhand and tried to go top shelf, but Halak made the save with the blocker.

The Flyers grabbed a 1-0 lead courtesy of the power play at the 7:47 mark of the second period. The Canadiens' penalty-killers did a good job of hemming the Flyers in the defensive zone early on, but Briere eventually emerged with the puck and led a rush the other way. The diminutive forward came across the offensive blue line and whipped a cross-ice pass to Umberger, streaking down the left side. Umberger collected the puck and, with a quick release, snapped a shot from the middle of the faceoff circle that beat Halak on the short- side.

Meanwhile, Biron continued to frustrate the Canadiens in the middle stanza, making 14 saves, including several of the jaw-dropping variety, to preserve the edge.