Though they fell to their closest Eastern Conference pursuer Saturday night in a brawl-filled game that evoked another era, the NHL-best Boston Bruins managed to answer one of the last lingering questions about themselves.

The Bruins, who face the red-hot Flyers on Tuesday night at the Wells Fargo Center, eased concerns about their toughness in the 5-3 loss to the Lightning, a defeat that ultimately might have done more for their Stanley Cup prospects than any of their league-high 43 victories.

The criticism arose in January, when, in a 3-0 loss to Columbus, the Bruins were slow to respond to a physical assault on goaltender Tuukka Rask. On Saturday, triggered by a questionable hit on forward Ondrej Kase, their players dropped their gloves on five separate occasions.

“There’s a value in sticking up for one another, there’s a value in responding,” Boston coach Bruce Cassidy said afterward. “Some nights it’s more important than the outcome. I’m not going to say it was one or the other. But we wanted to respond. After the high hit on Kase, we responded well and it was kind of on from there.”

Boston captain Zdeno Chara, who squared off with Tampa’s Pat Maroon in the throwback game that saw 26 penalties whistled, said the Bruins would be ready for teams who think they’re susceptible to an overly physical style.

“You’re going to have games where it’s going to get a little bit more chippy,” Chara said afterward. “We always put a lot of emphasis to have each other’s backs, and play as a unit. I thought you saw that tonight. Everyone responded in the right way.”

That’s not an encouraging development for the Flyers and the NHL’s other 29 clubs, all of whom understood even before Saturday that the Bruins were going to be a tough out in the playoffs regardless of how well and often they fought.

The Atlantic Division leaders arrive here with the league’s best record, 43-14-12. Their 98 points are six better than both East runner-up Tampa Bay and Western Conference leader St. Louis.

“The standings reflect it, but all you really need to do to see how good the Bruins are playing is to watch them,” Tampa Bay coach Jon Cooper said before his team split two recent games with Boston. “There aren’t many weaknesses.”

If nothing else, Boston’s reawakened rowdiness adds a little more appeal to Tuesday night’s already intriguing matchup with a Flyers team riding a nine-game win streak.

The matchup with a Bruins team that, according to statistics, at least, has the league’s best line, best defense, and best goalkeeper should provide the Flyers an opportunity to better assess themselves and their postseason prospects

The NHL’s statistical categories across the board are top-heavy with Bruins:

Their aptly named Perfection Line -- center Patrice Bergeron and wingers David Pastrnak and Brad Marchand -- has been the NHL’s top two-way unit this season. Outstanding defensively, on offense they’ve combined for 106 goals and 235 points.

Right-winger Pastrnak is the league’s goals leader (48) and is third in points (94). Marchand is sixth in the points race (86), while Bergeron has 30 goals.

Rask, their 32-year-old Finnish goalie, has a league-best 2.18 goals-against average. He has four shutouts and his .926 save percentage ranks second among goalies with at least 12 starts.

They have allowed the fewest goals in the league (165).

Torey Krug leads all defensemen in scoring with 49 points.

On special teams, their power-play percentage (25.1) ranks second, their penalty-kill percentage third (84.0).

Chara, Marchand, Bergeron, Pastrnak, and Charlie McAvoy all have plus-minus ratings of plus-20 or better.

And if all that weren’t impressive enough, the Bruins are resilient, able to withstand early-game emotional jolts like the Flyers, hyped up by a suddenly enthusiastic home crowd, hope to deliver. In games in which their opponents have scored first, the Bruins are 18-7-4.

Despite the fact that two of the biggest accomplishments in franchise history came at Boston’s expense – victory in the 1973-74 Stanley Cup Final and the astounding comeback from an 0-3 hole in the 2009-10 playoffs – Philadelphia historically has struggled with the Bruins.

Boston has the best all-time winning percentage against the Flyers (.557). With a 97-73-21 advantage, the Bruins are one of just two clubs (Montreal is the other) to have a historical edge on Philadelphia.

The Bruins had been relatively healthy this season, but in the two games with Tampa Bay they lost defensemen from their top two blue-line pairings. Brandon Carlo, who teams with Chara, missed Saturday’s 5-3 loss to the Lightning after getting elbowed in the head. And in that game, Krug, who has played alongside McAvoy, suffered an upper-body injury.

Neither will play Tuesday and Cassidy indicated that veteran defender John Moore would be active and that reserve Connor Clifton would see his first action since Dec. 29.