When he slides a sublime pass clear across the ice, past three defenders and onto the stick of a teammate, all eyes turn to see who will get the chance to score.

It is testament to R.J. Umberger, who started his postseason with a demotion to the fourth line, that the sellout crowd at the Wachovia Center ratcheted up its expectations last night as Umberger took aim on the net. Four games in, Umberger has turned into the Flyers' most feared scorer.

He scored the first goal of this series, in Montreal, then scored the first goal of Game 2. Now he was swooping in on goaltender Jaroslav Halak and firing a shot that billowed the netting and drew one of those head-inside-a-jet-engine roars from the crowd.

Flyers 1, Canadiens 0. For the fourth time in four games, the Flyers had scored first.

"It's huge," Umberger said. "They come hard and have a lot of great chances. When we score the first goal, they're like, 'Here we go again.' Those first goals are big in this series, especially."

This one was even bigger. Montreal coach Guy Carbonneau, giving off a faint whiff of desperation, decided to bench rookie Carey Price in favor of the seldom-used Halak. It was a risky move, and it didn't look too terrible after the teams skated through a scoreless first period.

It had to be tough for the Canadiens coach. His team has played superbly. The Canadiens are skating well. They're parking themselves in the Flyers' zone for long stretches. They're taking good shots and getting good position for rebounds.

They have lost three consecutive games (and trailed Game 1 until the final 30 seconds of regulation) for one reason.

Marty Biron. The Flyers goaltender really is the difference between the Habs and the Hab nots.

So if Halak could come in and give the Canadiens that same stone wall behind them that they've had in front of them, it could turn the series around. The Canadiens could regain home advantage, returning to Montreal with new confidence and a surge in momentum.

Then Umberger scored.

Fitting. He scored the last goal against Price in Game 3, prompting Carbonneau to pull the wide-eyed 20-year-old in that game. Now Umberger scored the first goal to welcome the new guy.

"If a team does that, they look desperate sometimes," Umberger said. "But I've seen backup goalies that are hungry come in and steal games. He's a good goalie that's young and capable, and he's playing for a full-time spot in the NHL."

Umberger has a full-time job, but not exactly a full-time spot. His scoring spree in this series is gratifying for a couple of reasons. First, he was demoted to the fourth line at the start of the playoffs and took the news as a reason to try harder, not to pout. Second, he is proving the importance of role players who come through when a team's stars aren't producing as much as needed to win.

"R.J.'s been terrific," coach John Stevens said. "He deserves a lot of credit. He's a man without a home, really. I've moved him all over the place for the good of the team. That's what makes him so valuable."

Stevens sat Umberger down and explained his demotion. He had come back from a knee sprain and wasn't as strong on the puck as he needed to be. Umberger wasn't happy, but he understood.

"I was looking forward to the playoffs all year," Umberger said. "I wanted to be a difference-maker for our team. I had to show [Stevens] that I was getting my back into it."

Umberger had stepped up to Jeff Carter's line after Mike Knuble had gone down with a hamstring injury during the Washington series. Although he had scored four goals in three games against the Canadiens, when Knuble returned last night, it was Umberger who moved again. This time, he skated on Mike Richards' line.

"Mike's a great player," Umberger said of Knuble. "That line has worked all year. There's great chemistry. I knew I would be moved off [the] line, and I was OK with that."

OK enough to score the first goal and the last goal. This time, Umberger tapped the puck into an empty net to seal another Flyers victory.

He has seven postseason goals, third in the NHL behind Briere and Detroit's Johan Franzen, who are tied with eight each.

The Flyers now have three chances to close out the Canadiens and complete the biggest upset of the Stanley Cup tournament so far. Montreal will fight hard. It will be interesting to see which goaltender Carbonneau decides to start.

Thanks to the man without a home, the Flyers know they can beat either one.

phil_sheridan. Or by e-mail: psheridan@phillynews.com.