TAMPA, Fla. -- Ninety minutes before the opening faceoff, Jon Cooper talked about what the Tampa Bay Lightning needed to do to get back on track in the Eastern Conference finals.

"We've got to play better," the coach said. "That's it."

Ryan Callahan provided an early spark, Andrei Vasilevskiy made two big saves in the closing minutes to avoid a total third-period collapse, and the resilient Lightning held Friday night for a 4-3 victory over the Pittsburgh Penguins in Game 4 of the Eastern Conference finals.

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Callahan tipped a shot past goalie Matt Murray just 17 seconds into the game. Andrej Sustr, Jonathan Drouin and Tyler Johnson also scored and the Lightning rebounded after being badly outplayed in the previous two games to even the series 2-2 heading back to Pittsburgh for Game 5 on Sunday.

"The one thing on the bench was, it doesn't matter how you get there," Cooper said after the Penguins scored three times in 12 minutes to turn a potential rout into a nail-biter.

"So whether you're up 4-0 and it becomes 4-3, or you're down 3-0 and it becomes 4-3, it doesn't matter. You're still winning, so you've got to play like that," the coach added. "Ultimately, the goal is to win the hockey game, and when you wake up in the morning, it's not how they came back and made it a game. Ultimately, the series is 2-2."

Vasilevskiy had a 4-0 lead entering the third period, but the Penguins didn't give up. Phil Kessel and Evgeni Malkin scored to give Pittsburgh hope, and Chris Kunitz's power-play goal trimmed the deficit to one with a little less than 7 minutes remaining.

"We were not the more determined team for the first half of the game," Penguins coach Mike Sullivan said. "They are a good team, and we knew this was going to be a hard game."

Tampa Bay was outshot 16-7 over the final 20 minutes after dominating the first two periods. Malkin and Jason Schultz tested Vasilevskiy in the final 2:10, but Vasilevskiy stopped both efforts to tie the score.

The 21-year-old goaltender, filling in for injured Vezina Trophy finalist Ben Bishop, finished with 35 saves in his fourth career playoff start.

Marc-Andre Fleury replaced Murray in goal for the Penguins at the start of the third, and Kessel's team-leading eighth goal began the rally that just fell short.

The Lightning were outshot 89-49 in the previous two games, a disparity that Cooper called "unacceptable" after the Penguins took a 2-1 series lead.

But the experience of the highs of lows of last year's playoff run to the Stanley Cup final has served the defending conference champions well over the past month.

While acknowledging there was a sense of urgency to play better, Cooper and his players insisted the team was not overly discouraged after being badly outplayed in Games 2 and 3 because they been down in series before and found ways to come back.

Callahan's first goal since Game 3 of the Lightning's second-round win over the New York Islanders got them rolling. Sustr's second career playoff goal -- first this postseason -- made it 2-0 at 14:28 of the opening period.

#BOLTS WIN! BOLTS WIN! SERIES TIED!⚡️⚡️⚡️⚡️ pic.twitter.com/EdzTTWIiCA

— #GoBolts (@TBLightning) May 21, 2016

Drouin and Johnson -- playing with a full cage and later a plastic shield on his helmet after taking a puck to the face during warmups -- scored in the second to build the lead to 4-0. Drouin scored with a minute left in a four-minute power play that Penguins were unable kill with defenseman Kris Letang in the penalty box for cross-checking and roughing.

The Penguins, relentless in Game 3 when they took 48 shots en route to a 4-2 victory, were unable to convert a couple of good scoring chances in the first period and had limited opportunities until finally cracking Vasilevskiy in the third.

Kessel scored at 1:18 of the third period, beating Vasilevskiy from above the right circle. The goal was his team-leading eighth of the playoffs, with Nick Bonino and Brian Dumoulin picking up assists.

Malkin scored at 11:13 and the Penguins drew closer when Kunitz added his goal with 6:52 remaining.

This is how we Drouin 🔥 #PITvsTBL https://t.co/eLyouCvg7R

— #GoBolts (@TBLightning) May 21, 2016

Penguins captain Sidney Crosby said the slow start was not as "horrible as it was made out to be," noting Tampa Bay entered the night as the more desperate team after losing two straight.

"It wasn't the start we wanted for sure," Crosby said, "but we still had our chances to get back into the game before it became 4-0."

Notes: Murray stopped 26 of 30 shots through two periods. Fleury finished with seven saves. ... Injured Lightning captain Steven Stamkos continues to practice, however there's still no definitive timetable for a possible return from surgery for a blood clot discovered near his right collarbone. "I'm hoping to, but there's still a real possibility that I may not play at all in the playoffs. It's tough when you have two different parts of the spectrum," Stamkos said. "It's either you're going to be able to play or it's just not safe to play. So we still haven't come to that decision yet. That's going to take a lot of information gathering and a lot of different opinions."... Penguins RW Patric Hornqvist played after missing the closing minutes of Game 3, when he was shaken up blocking a shot. ... Both teams went 1 of 4 on power-play opportunities.