Updated

There was no comeback for Alex Ovechkin and the Washington Capitals against the Tampa Bay Lightning — only more postseason disappointment.

Falling short of expectations yet again, the top-seeded Capitals were swept from the NHL playoffs on Wednesday night, falling 5-3 to the fifth-seeded Lightning in Game 4 of the Eastern Conference semifinals matchup.

"It was a tough year — we went through peaks and valleys — but I just thought if we persevered that something good was going to happen," Washington coach Bruce Boudreau said.

"I thought as late as when they made it 5-2, this is going to be tough. But even before that I thought, 'OK, we're going to find a way. The guys want it too much, and they've come back all year in dire straits.' I still thought we were going to tie it up and win it in overtime."

With chants of "sweep, sweep, sweep" reverberating through the building, the Lightning had other thoughts and kept pushing until Washington had no more hope.

Sean Bergenheim scored two goals and Dwayne Roloson stopped 33 shots for Tampa Bay, which extended its winning streak to seven games and advanced to the conference finals for the first time since its 2004 Stanley Cup championship season.

"We're definitely happy, but we're not popping champagne or anything," Lightning forward Ryan Malone said. "We know what our goal is and we have to keep going and stay even keel. We haven't done anything yet."

Rookie Michal Neuvirth stopped 32 shots for Washington, but Bergenheim scored twice in eight minutes during the second period to build a 3-1 lead that sent the sellout crowd of 20,835 into celebratory mode long before it was over.

"There's not very much you can say. They're down in the dumps. I'm down in the dumps," Boudreau said. "I just told them I was proud of them for the way they worked all year, and that they never quit right to the end. That's all a coach could ask is if you don't quit and you just keep plugging through. I thought we had a good chance to win, and we just didn't get it done."

The Lightning's big three of Martin St. Louis, Vincent Lecavalier and Steven Stamkos have elevated their games in the playoffs, but so has Bergenheim, who has a team-leading seven goals through two rounds. St. Louis' sixth goal of the playoffs, with 3:08 remaining, finished Tampa Bay's scoring.

Malone and Marc-Andre Bergeron added goals for the Lightning, who have not lost since dropping into a 3-1 hole against the Pittsburgh Penguins in the first round.

Bergenheim was eighth on the Lightning with 14 regular-season goals, however he's been much more of an offensive force in ousting the Penguins and Lightning.

It's something coach Guy Boucher, who has Tampa Bay in the conference finals in his first season as an NHL coach, has come to expect of the forward.

"Every top game, every important game, every game that there is some pressure, he was in it. He was one of our better players," Boucher said. "Some people freeze under pressure, some people fly away, and some people fight. He fights."

Marco Sturm, John Erskine and John Carlson scored for the Capitals. Ovechkin had an assist on Sturm's goal, but couldn't find the net with any of five shots at the 41-year-old Roloson, a midseason acquisition who is one of the biggest reasons Tampa Bay not only is in thep playoffs for the first time since 2007 but thriving.

"When they got Dwayne Roloson, they became a completely different team," Boudreau said.

The Lightning won the first two games of the series in Washington, then pushed the Capitals to the brink of elimination by winning Game 3 in Tampa on Tuesday night.

They were expecting the toughest game of the series Wednesday, calling the Capitals a proud team that would not be taken lightly. Washington felt the first three games could have gone either way, with Ovechkin insisting after Game 3 that the series was far from over and that he expected his team to come back and win.

"We were hungry and we wanted to win," Ovechkin said. "We wanted to win. They wanted to win. Somebody had to lose. I don't know what to say right now."

The Capitals went 1 for 3 on the power play in Game 4, finishing 2 of 19 for the series. Tampa Bay had two power-play goals Wednesday night alone.

"When they had a chance to score, they scored. We didn't," Ovechkin said.

"It's very frustrating. I don't think any of us saw this coming down, happening like it did. Probably the last thing that was in our mind, but you have to give them credit," Capitals forward Mike Knuble said. "They played well, and they held their own when they had to. And really, when they got their chances they capitalized. It was pretty amazing how well they could do it."

NOTES: St. Louis, Lecavalier and Kubina are the only players remaining on the Lightning roster from the Stanley Cup championship team. ... The Lightning have won eight consecutive postseason games against the Capitals, dating to the first round in 2003. ... Ovechkin finished with five goals and five assists for 10 points in nine playoff games.