BOSTON — The likelihood that this will become the norm, and not the exception, isn’t very high.

For one night, though ... so what?

The Boston Bruins needed a lift after their leader in goals (31) and points (66), David Pastrnak, underwent thumb surgery on Tuesday morning, and they gave it to themselves on Tuesday night.

Making their final TD Garden appearance until Feb. 26, the B’s matched their second-highest goal total of the season in a 6-3 decision over the Blackhawks that extended streaks jeopardized by Pastrnak’s sudden absence: The Bruins won their third in a row and earned a point for the eighth straight game (5-0-3), and they did it by beating a team that rode a seven-game winning streak into Boston.

“Obviously, you don’t want a guy like that hurt,” center David Krejci said of Pastrnak, whom general manager Don Sweeney said hurt himself in a fall after while walking with teammates from a sponsorship dinner after Sunday’s 2-1 win over the Avalanche. “But if a guy like that is hurt, another guy has to step up. It means more opportunity for other guys.”

Danton Heinen and Jake DeBrusk, a pair of second-year B’s who haven’t matched their rookie seasons, seized their opportunities with both hands.

Heinen, in fact, actually continued to take advantage of a new lease on life. In his third full game since replacing Pastrnak on the top scoring line with Brad Marchand and Patrice Bergeron, Heinen had a goal (ninth of the season) and two assists — one on Marchand’s 22nd goal of the year, the other on a power-play goal by Peter Cehlarik.

DeBrusk, recently relegated to third- and fourth-line duty, moved back onto Krejci’s No 2 line and had a three-point night. The goal, his 15th this season, ended a 13-game drought.

“We’re going to need contributions from everybody with (Pastrnak) going down for a bit,” Marchand said of his for-now former linemate, who is expected to miss a minimum of two weeks. (Pastrnak moved last week to Krejci’s line, as coach Bruce Cassidy sought to balance the Bruins’ scoring.)

“Heinen was unreal tonight, made a lot of big plays. Jake was very clutch as well. It’s fun to see them play like that. They add so much depth to our group. ... We need that to continue.”

The Bruins, who feel they’ll probably have to close ranks and tighten their already formidable team defense while Pastrnak heals, weren’t always great without the puck on Tuesday, but a key defensive sequence kept them close when the game could have gotten away: Trailing 1-0 after Tuukka Rask (23 saves, now 10-0-2 in his last 12 decisions) allowed a super-soft goal to Alex DeBrincat after just 4:22, the Bruins — primarily Bergeron, Kevan Miller and John Moore — killed a 49-second, 3-on-5 disadvantage, with penalty-killing specialists Marchand and Zdeno Chara serving the penalties.

Goals soon came from Krejci (power play, on a one-timer reminiscent of so many of Pastrnak’s league-high 15 power-play goals), Heinen and new scoring leader Marchand, whose goal and three assists extended his points streak to five games (3-9--12) and pushed him to 69 points for the season — three better than Pastrnak.

The Bruins’ first three-goal lead (4-1) came off DeBrusk’s goal with 1:54 left in the second, but they let the Blackhawks whittle that to 4-3 in the third before Cehlarik (off a great pass from Heinen) and Krejci closed the scoring.

Bruce Cassidy, who collected his 100th win in Game 166 of his tenure as Bruins head coach, praised the team’s “buy-in” with Pastrnak out.

“We stuck with it,” the coach said, “and eventually got rewarded.”

The Bruins, whose eight-game streak has allowed them to move within one point of the second-place Maple Leafs in the Atlantic Division, now hit the road for five straight games against Western Conference teams, starting on Friday night in Anaheim.

“Obviously, we’re fighting for a position right now,” Marchand said. “We want to continue to move up in the standings, so it’s a big road trip.”