The Capitals scored a series-high five goals in Game 6 to stun the Penguins in Pittsburgh. (John McDonnell/The Washington Post)

PITTSBURGH — This Capitals-Penguins series is headed to Game 7. Could it have ended any other way?

Washington kept its season alive with a 5-2 win over Pittsburgh at PPG Paints Arena on Monday night. That forces a decisive seventh game Wednesday at Verizon Center, with the winner advancing to the Eastern Conference finals and the losers heading to an early start on summer vacation.

It was the second consecutive do-or-die victory for the Capitals and came in a game in which the Penguins trudged through a lethargic performance.

Here is how the series looked immediately after Game 6 ended. (There is hope for the Capitals.)

Capitals grab momentum from the start 

The Capitals couldn’t win a faceoff to save their lives in the first period, yielding 20 of 28 to the Penguins. But the Capitals still had an 11-3 advantage in shots on goals after the first 20 minutes and held the most important edge: 1-0 on the scoreboard after T.J. Oshie netted a power-play goal.

The team that scored first was 4-1 in the series heading into Monday, but that wasn’t the Penguins only problem in the first period of Game 6. Of their three shots on goal in the first, one was essentially a clear during a penalty kill, another was a half chance on a power play and their first five-on-five shot came with 1.1 seconds left in the period.

On their lone power-play opportunity, Patric Hornqvist went to the locker room after seemingly taking a Matt Niskanen skate to the face. Moments before that, Sidney Crosby went head first into the bottom of the boards after getting tangled up with Hornqvist and John Carlson. Crosby, who sustained a concussion exactly one week ago on a high cross-check by Niskanen, was not pulled from the ice even though he was slow to get up.

Crosby and Hornqvist both returned for the second period, and the Capitals stretched the lead to 2-0 on an Andre Burakovsky goal 6:36 into the second. From there, the Capitals slowly buried the Penguins in a game the home team didn’t show up in until it was too late.

Penguins’ top line completely flat, and the team follows 

The Penguins were outshot 16-8 through the first 40 minutes, and were hearing from boos from their home crowd as they headed into the locker room down 2-0 after two periods.

But within their lethargic start was a limp effort by their top line of Conor Sheary, Crosby and Hornqvist.

Sheary put two shots on goal late in the second period, but Crosby and Hornqvist headed into the final frame without zero apiece. Nicklas Backstrom then buried the stumbling Penguins with a goal on the first shift of the third period. A goal from John Carlson followed, and then another from Andre Burakovsy. By that time, the Penguins minuscule chances of a comeback were completely wiped away. Even two late goals could not change that.

Burakovsy keeps benefiting from Trotz’s line changes 

Burakovsy found his rhythm after he was moved to the top line for Game 5, and that carried into Game 6 when he made a stellar scoring play in the second. Burakovsky checked defenseman Ron Hainsey along the boards, collected the loose puck, coasted to the right post and sneaked an odd goal past Marc-Andre Fleury. It was his second goal in as many games, and his second of the postseason. He got his third goal in the final period, as he waited for the perfect moment to sling a wrist shot past Fleury and give the Capitals a 5-0 lead.

In Game 5, Trotz looked like a genius after moving Burakovsky to the first line and Alex Ovechkin down to the third. Burakovsky scored his first goal of the playoffs with the third line, assisted on a Backstrom goal on the first line and then Ovechkin topped things off by scoring on the third line with Lars Eller and Tom Wilson. Trotz stuck with the line configuration for Game 6.

Penguins Coach Mike Sullivan also tinkered with his lines, restoring the vaunted third line of Carl Hagelin, Nick Bonino and Phil Kessel, who lit up the Capitals with five goals in last year’s second-round series, for Game 6.

“Washington has a lot of balance in their lineup, we have a lot of balance in our lineup,” Sullivan said Monday morning. “I’m not sure you advance this far as a team if you don’t have that balance.”

For the second consecutive game, the Capitals’ offensive balance won out.

Holtby is strong until the end; Fleury struggles

Braden Holtby had a shutout until the Jake Guentzel and Evgeni Malkin scored in the final minutes. The Capitals goalie ended with 14 saves in the two-goal performance. Fleury, on the other hand, allowed five Washington goals and made 21 saves.

Fleury allowed one goal and made 10 saves in the first period. In the second, Fleury allowed a questionable Burakovsky goal but was otherwise clean, while Holtby discarded all eight (yes, eight) of the Penguins’ chances through two periods, including just three in the first period.

Each goaltender had one notable hiccup in the first five games of the series, Holtby’s coming in Game 2 and Fleury’s coming in Game 5. Holtby allowed three goals in 14 shots in the first two periods of Game 2 and was pulled at the start of the third of an eventual 6-2 loss. Fleury allowed four goals in Game 5 — three coming in a 4:58 span — the most the Capitals had scored in the series.

“Just today, in general, probably was my worst one in all the playoffs, I think,” Fleury said after Game 5. “I don’t know, I kind of want to forget about it quickly and move on.” Fleury’s teammates shouldered the blame after Game 5, saying they could have played better in front of the goaltender and spent more time in the Capitals’ zone.

The Penguins, who already had been playing without top defenseman Kris Letang, were missing defenseman Trevor Daley (lower-body injury) Monday. Whoever was to blame Monday, Fleury was leaky and the Penguins’ offense waited way too long to get going against Holtby and the Capitals.

Kuznetsov keeps contributing 

Evgeny Kuznetsov was involved in the Capitals’ offense from the start of Game 6, assisting on Oshie’s power-play goal to start the scoring in the first period. It came as Kuznetsov moonlighted on the Capitals’ first power-play unit, and the goal was set up by a pinpoint pass that set up Oshie’s one-time shot from the slot.

That gave the Capitals a lead despite losing 12 of the game’s first 15 faceoffs; they had it coming after jumping out to a 7-0 lead in shots on goal. It also was further illustration of how important Kuznetsov has been to the Capitals throughout this series.

Trotz has kept the second line together while shuffling his forwards throughout the postseason. That is likely, at least in part, because of how well Kuznetsov plays with top-liners Justin Williams and Marcus Johansson on his flanks. The 24-year-old Kuznetsov scored in Games 1, 3, 4 and 5 and added an assist in a Game 3. His goal in Game 5 was the game-winner.

“Once you take the responsibility of being a difference-maker or a guy who will be required or be responsible to be a difference-maker, then it’s a little bit different mind-set,” Trotz said earlier in the series. “And I think he’s crossing over. He knows that he’s got to be a difference-maker and he’s going to play against top guys and he’s going to be a guy that can’t take minutes off and has got to be detailed and has got to fight for his inches.”

His contributions in Game 6 weren’t loud by any measure, but Monday offered another display of his ability to (subtly or not) consistently affect games.

Isabelle Khurshudyan contributed reporting