The Washington Capitals stacked the deck Monday night by fielding their optimal lineup for the first time this season — and then looked woefully out of sync. Early on, the Capitals failed to execute passes and lost board battles as the Columbus Blue Jackets unmercifully peppered goaltender Braden Holtby.

The Capitals team that came in riding a six-game winning streak saw it snapped in unceremonious fashion during a 5-2 loss at Capital One Arena, unable to return to the well-rounded game it has played over the past two weeks.

“That’s a good thing about this league: Everyone can beat everyone if you don’t have your best day,” said center Nicklas Backstrom, whose return after missing eight games with an upper-body injury made the Capitals’ lineup whole. “Columbus is good. They’re a good hockey team. But that’s not the way we wanted to play — that’s for sure.”

Washington (22-5-5) struggled on both ends of the ice against Columbus (12-14-4) and couldn’t create many scoring chances early against a Metropolitan Division opponent that entered the contest on a four-game skid. Trailing 2-0 going into the third period, the Capitals finally started to find their game as they got goals from Alex Ovechkin and Backstrom, but by then it was too late — and Columbus answered each time.

“There wasn’t a whole lot going right,” Capitals Coach Todd Reirden said. “That was, to me, one of our worst two periods of the year. . . . Our execution was off, and our goaltender played phenomenal in the first to give us a chance. A major credit to him for the first period . . . but the play other than that was unacceptable.”

Ovechkin scored 40 seconds into the third period to cut the Blue Jackets’ lead to 2-1 by corralling a rebound and sneaking it past Blue Jackets goaltender ­Joonas Korpisalo. It was his 21st goal of the season and the 679th of his career. He is six goals shy of passing Teemu Selanne (684) for 11th in NHL history.

But Columbus responded with 13:07 left on a goal by Riley Nash.

“They played a really good game,” said Holtby, who made 33 saves. “In the end, [Nash’s] goal killed us, and move on.”

Oliver Bjorkstrand stretched the Blue Jackets’ lead to 4-1 at 10:37 before Backstrom scored at 17:54 with Holtby on the bench for an extra attacker. Reirden had pulled Holtby with about five minutes left, sent him back on the ice after forward Tom Wilson took a penalty and then pulled him again, leading to Backstrom’s goal. But Columbus again came right back with an empty-netter from Cam Atkinson at 18:12.

“There’s a number of different things that factor into [pulling a goaltender that early],” Reirden said. “I wanted to go even a shift earlier, and we couldn’t get possession. Something I wanted to add this year is pulling him a little bit earlier and giving ourselves a chance.”

Washington was coming off a 4-0-0 road trip that included a three-game sweep of the NHL’s California teams for the first time in franchise history. Monday’s loss was its first in regulation since a 4-1 defeat at the New York Rangers on Nov. 20. Despite the loss, the Capitals still sit atop the league with 49 points — and they host the No. 2 team, the Boston Bruins (20-5-6, 46 points), on Wednesday night.

“We’ve just got to regroup, and hopefully it’ll be a fun game on Wednesday,” Backstrom said.

The Capitals’ full lineup wasn’t enough to get them a win against Columbus, but it was a good sign for the team to reach full health more than a third of the way through the season. Washington had gone its first 31 games with at least one player injured or suspended. Backstrom’s return ended that; he was slotted on the top line with Ovechkin and Wilson, but the group failed to create any offense until the captain’s goal early in the third.

“It’s going to go through a little bit of a growing period here with having our full group back,” Reirden said.

The Capitals were outshot 20-6 in the first period as the Blue Jackets commanded both ends of the ice. That shots-against total was a single-period high for Washington, and Atkinson opened the scoring on a redirect at 3:27.

Holtby was one of the only reasons the Capitals weren’t down by a larger margin early. He had 19 stops in the opening period, including a handful of diving efforts against the team that entered 30th in the 31-team league in scoring.

Columbus went ahead 2-0 at 6:52 of the second period after a great passing sequence got the puck to defenseman Ryan Murray, who beat Holtby. Capitals defenseman Nick Jensen had lost a board battle behind the net and lost the puck.

Washington tried to find a spark later in the period by boosting its physicality, with Ovechkin delivering six hits after notching two in the first. Despite the uptick in physicality and two power-play chances in the period, the Capitals could not get the puck past Korpisalo, who finished with 37 saves. Before Monday, the Capitals had been 4-3-1 when trailing after two periods.