Devante Smith-Pelly, center, celebrates his goal during the regular season. (AP Photo/Nick Wass)

PITTSBURGH – The Washington Capitals would normally take a day off after clinching a playoff series, but they would especially need a 24-hour window to decompress after beating the Pittsburgh Penguins, 2-1, in overtime on Monday night to advance to their first Eastern Conference finals in 20 years.

There would be no more celebrating on the off-day Tuesday, just rest for a roster that has very little experience playing this deep into the playoffs. The Capitals will then turn their attention to the Tampa Bay Lightning, which has won plenty in the postseason over the past four years and is back in the conference finals for a third time in four seasons after cruising past Boston, 4-1, in the second round.

The Lightning, which entered the postseason with an Eastern Conference-best 113 points after finishing 54-23-5 in the regular season, is 8-2 in the playoffs – its only other loss came in Game 3 of its first-round series win against the New Jersey Devils.

“We get a chance against another opponent and we’re gonna have to be at our best as it goes along here,” Washington Coach Barry Trotz said. There’s going be four teams left and you don’t get these opportunities too often.”

Here’s a look back at the three meetings between the Capitals and Lightning during the regular season.

Oct. 9: Lightning 4, Capitals 3 (OT). Tampa Bay dealt the Capitals their first loss of the season on a power play in overtime, which also snapped a string of 13 penalty kills to open the series. Washington’s penalty kill should again be at the forefront of this series with Tampa Bay. The Capitals hold a 79.1 penalty kill percentage in the playoffs, which is second best among teams remaining, and the kill unit will be bolstered by the return of Tom Wilson off his three-game suspension for Game 1.

Nov. 24: Capitals 3, Lightning 1. This win marked the first of the season for goaltender Philipp Grubauer, who finished with 25 saves in the kind of performance that made him one of the league’s most productive goalies through the first few months of the season. Grubauer would go on to start the first two games of the postseason before getting pulled for Braden Holtby, who has played motivated hockey ever since. Holtby is 8-3 since and posted one of his best performances in Game 6 against Pittsburgh, allowing just one goal on 22 shots. His postseason save percentage is .926, which is up from .909 in the payoffs a year ago.

“Outstanding. Ever since we put him back in, he doesn’t want to give up the net anymore and he’s been fantastic,” Trotz said of Holtby. “I think you’re seeing another level of Braden and with our team as well.”

Feb. 20: Lightning 4, Capitals 2: This loss was a low point of Holtby’s midseason slide. But it was also reflective of the struggles of Washington’s defense in front of the net. A day before this loss, which came even as Washington outshot Tampa Bay 37-19, the Capitals made a move to acquire Michal Kempny from Chicago. He didn’t play that night against the Lightning, but since he made his debut the following game against Florida, he has helped Washington’s defense trend upward to this point in the playoffs. That included holding a loaded Pittsburgh lineup in check during Game 6.

“They’re a hell of a hockey team,” Trotz said of the Penguins on Monday night. “We’re only halfway. We haven’t done anything yet. It’s a good feeling getting by the Penguins because there’s a lot of skeletons in the closet. It’s a start.”

Read more on the Capitals:

The 13 excruciating playoff losses that had D.C. sports fans starving for one more Capitals win

Capitals’ win puts a dagger in the D.C. sports ‘curse’

Sudden end leaves Penguins in unfamiliar position

Washingtonians go bonkers after Caps’ overtime win

Evgeny Kuznetsov’s winner: Watch it, listen to it, never forget it

That Caps win was Washington’s biggest since …