TAMPA, Fla. — Maybe the Eastern Conference finals were destined to go seven games, what with the Tampa Bay Lightning[1] and Pittsburgh Penguins[2] battling with equal p arts grit and guile. But the Penguins had raw desperation on their side Tuesday and the return of the rookie goaltender Matt Murray, and they skated to a 5-2 victory.

Pittsburgh evened the series at three games each, turning back a third-period rally by the Lightning, who are looking to become the first team to reach back-to-back Stanley Cup finals since the Penguins in 2008 and 2009.

Bryan Rust clinched it on a breakaway goal, and Pittsburgh added an empty-netter to stave off elimination and soften criticism of Coach Mike Sullivan's flip-flopping of goaltenders.

Murray made 28 saves, including several spectacular stops in the final minutes as Tampa Bay rallied from a 3-0 third-period deficit.

Pittsburgh built a 2-0 lead on goals by Phil Kessel and Kris Letang, who scored at 7 minutes 40 seconds of the second period when he and Conor Sheary broke into the Lightning zone after turnover. Sheary left a smooth drop pass to Letang, who ripped a wrist shot high into the left corner.

Two-goal leads have evaporated like swamp water under the Florida sun in this series, but Sidney Crosby eased some pressure when he caught Anton Stralman and Nikita Kucherov on their heels with 26 seconds remaining in the period. Crosby skated around both defenders for a clean breakaway and beat goaltender Andrei Vasilevskiy for a 3-0 lead.

Still, the Lightning rallied, cutting their deficit to 3-2 with seven minutes to play. Brian Boyle scored both goals, throwing the puck in front of the net and having it hit Kessel's stick and skate for one and then firing a wrist shot high over Murray's right shoulder.

Pittsburgh held the edge in shots after two periods, 26 to 11. Tampa Bay slowly recovered after being deflated by a disallowed goal about five minutes into the game.

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The Penguins did not need extra motivation or help in trying to extend the series to a seventh game Thursday night in Pittsburgh. But the Lightning provided both with back-to-back head-scratching penalties late in the first period that led to a 1-0 lead for the Penguins.

First, Stralman was called for interference after decking Tom Kuhnhackl near center ice as the puck passed them both. Then, 41 seconds later, Victor Hedman cleared the zone by firing the puck almost the length of the rink, over the head of Murray and into the netting that protects fans, resulting in a delay-of-game call.

That gave the Penguins a two-man advantage, and they quickly converted. Crosby faked a slap shot from the right face-off circle and directed the puck to Kessel near the left goal post, who chipped in a shot past Vasilevskiy with 74 seconds left.

Pittsburgh's momentum had surged since midway through the first period, when the Lightning briefly celebrated a goal by Jonathan Drouin, only to have it disallowed. The Penguins quickly challenged that Drouin, who was trailing the play, was offside on the scoring rush. Replays clearly showed that Drouin's left skate was slightly in the air as his right skate crossed the blue line.

From there, energy shifted to the Penguins, who outshot the Lightning by 14-4 in the first period, and helped justify Sullivan's decision to start Murray after benching him for the veteran Marc-Andre Fleury in Game 5.

Sullivan had pushed mostly right buttons in his five months as Penguins coach, but many found the move puzzling. Fleury had played the third period of Game 4 and started Game 5 despite not having played since March 31 after sustaining a concussion.

But Sullivan was convinced Fleury was ready even though Murray had fashioned a 9-4 record these playoffs. The switch backfired somewhat, and then Sullivan reversed course and was not afraid to second-guess himself.

"He's won a lot of big games for us," Sullivan said of Murray before the game. "He's made timely saves for us. He has a demeanor back there, a calming effect on the group in front of him. I think his performance speaks for itself.

"At this particular point in the season, we don't have the luxury of allowing players to play through things. We have to win a hockey game. That's how we looked at it."