The NHL playoffs are about seeing the job through. They require a grinder's mentality and a finisher's touch.

And quite often, they are about endurance - not just through four rounds of best-of-seven series, but also through multiple overtime periods.

Coach John Stevens got his first taste of double overtime last night at the Wachovia Center, where the Flyers beat the Washington Capitals, 4-3, on Mike Knuble's goal 6 minutes, 40 seconds into the second extra session.

"If I'm not around the net, I don't have much chance scoring goals," Knuble said. "That's my identity as a player. Some days they come to you and some they don't. The puck might bounce around. Today, it came to me. It took two whacks to get it in.

"What a huge thrill just to hear the building explode. It's an unbelievable feeling. You wish you could bottle it up for next time."

The Flyers' victory gave them a three-games-to-one stranglehold on the series, which could end tomorrow in Washington. Truth be told, the Caps outplayed the Flyers in regulation time with their most aggressive style of the series, but the Flyers had the edge in the overtime periods.

"It was a lot of fun," center Danny Briere said. "It was pretty cool the way we took over that game late in the first overtime and then the second overtime. I thought we were the much better team."

Flyers goalie Marty Biron, who made 38 saves, and the Capitals' Cristobal Huet, who made 43, had solid games.

The Flyers trailed, 3-2, about halfway through the third period when Huet made a spectacular diving save across the crease to deflect Scottie Upshall's shot with his glove hand. The puck was headed for an empty net.

"He made that great save on me. He really stepped up," Upshall said. "The Capitals really played a great game. I give them credit. I expect them to come out like that on Saturday."

Seconds later, Washington was hit with a penalty for too many men on the ice, and Briere tied the score with his team-high fifth goal of the playoffs on a tough pass from Mike Richards.

"We were patient, and we got rewarded with that power play," Briere said. "We really controlled the puck. Richie made a great pass to find me backdoor."

Biron made a critical glove snare of David Steckel's drive from the slot with less than six minutes to go in regulation time.

Three minutes later, Biron made a pad stop on Viktor Kozlov, who had stripped Braydon Coburn of the puck on the breakout. That got the Flyers into overtime.

In the first overtime, Biron made a marvelous save on Alexander Semin off a draw with 7:15 remaining in what had turned into pond hockey.

Jeff Carter's line provided three of the Flyers' four goals.

"Just seems like they're a line that is ready to help us win a hockey game," Stevens said. "That line was tremendous, and they played the bulk of their minutes against [Alexander] Ovechkin's line."

Several things stood out in this one.

First, the Capitals had their most aggressive start of the series. Second, the Flyers continued to have trouble with their power play, which was second in the league during the regular season. They were 1 for 7 on the power play last night.

And the ice seemed poor, even though ice guru Dan Craig was in the building. Perhaps it was because yesterday was the warmest day of the spring at 70 degrees.

But the most impressive difference was Washington coach Bruce Boudreau's moving Ovechkin off the point on the power play, into the low slot. The result? The Russian winger had two power-play assists in the first period.

"You have to give them credit," Briere said. "They battled hard tonight. They were hungrier for pucks. That's why it took so long for us to clinch it."

Carter scored two goals in the first period.

"The first goal was a turnover by them," Carter said. "Knubes made a great play, and I was lucky to get it on net. The second goal was set up with a great pass by Mo [Jaroslav Modry]. I just kind of snuck in the far side there and I had a wide-open net."

The early goal gave the Flyers energy and got the crowd into it.

Washington got goals from Nicklas Backstrom and Semin in the first period, then took its 3-2 lead in the second period on a short-side goal by Steve Eminger, with Biron on his knees instead of standing tall at the post.

Biron made up for it in spades in the overtime periods.

"We fell behind and came back," Knuble said. "We were probably as exhausted as our fans, and none of us will get any sleep tonight. What a great feeling, though, going to Washington up 3-1."