PHILADELPHIA • The Blues were aware of the degree of difficulty in their four-game road trip, but this might be more than they expected.

The visitors fell 4-1 to the Philadelphia Flyers in a Saturday matinee at the Wells Fargo Center, dropping to 0-2 on the trip.

The Blues broke out of a scoring slump that saw them shut out in Chicago on Wednesday in the first game of the trip. But despite outshooting Philadelphia 33-19, they had only a shorthanded goal by Jaden Schwartz to show for their day against the Flyers.

“It was a big goal at the time,” Schwartz said.

But Scott Hartnell and Brayden Schenn helped Philadelphia overcome a one-goal deficit with a pair of second-period goals and Steve Mason preserved the lead with some third-period theatrics in net, leading the Flyers to their fifth straight victory.

The Blues still clinched a playoff spot, when Phoenix lost to the Boston Bruins late Saturday night.

But they had an opportunity to stamp their playoff ticket themselves as late as midway through the third period when they trailed Philadelphia 2-1.

Surviving a scare when T.J. Oshie headed to the locker room but returned after blocking a shot with his hand, the Blues put some pressure on the Flyers with nine minutes left in regulation. But Mason came up with a dandy leg save on Schwartz and denied Derek Roy on two follow-up attempts.

“I thought (Mason’s) level of competition was harder than ours in and around the net area,” Blues coach Ken Hitchcock said. “We hit a lot of goal posts and crossbars, but I don’t think we had the second and third chances as the game wore on that we did in the third period.”

Philadelphia’s Jakub Voracek answered with his 19th goal of the season with 4:19 remaining and, after the Blues pulled goalie Ryan Miller with three-plus minutes to play, Wayne Simmonds added an empty-netter with 2:54 to play.

The victory continued a stretch in which the Flyers have beaten Pittsburgh twice, Chicago and now the Blues.

“They’ve beat a lot of good teams in the recent past,” Blues captain David Backes said. “They made no mistake when they had the lead ... they took it to us.”

A game that figured to be hard-checking started out fast-skating, but it didn’t take long for the feistiness to emerge. Barret Jackman tripped up the Flyers’ Zac Rinaldo, leading to the first power play of the game.

The Blues’ penalty-killing unit had erased 24 of the last 26 man-advantages it had seen — allowing two in Wednesday’s loss to Chicago — but the group did better than erasing the infraction on Jackman.

Schwartz and Kevin Shattenkirk went on a shorthanded 2-on-1 break and the winger received a slick centering feed from the defenseman, leading to Schwartz’s 22nd goal of the season just 6 minutes 24 seconds into the game.

It was Schwartz’s second shorthanded goal in 2013-14, the fourth for the year for the Blues, and the 11th allowed by Philadelphia — tied for most in the NHL.

Saturday’s game featured 18 minor penalties, and the last one of the first period led to the only power-play goal of the game, which turned out to be the game-winning goal.

Vladimir Sobotka was called for hooking Hartnell with seven seconds left in the period, and then 57 seconds into the second period Hartnell knocked in his 19th goal of the season for a 1-1 tie.

The second period started off poorly for the Blues and continued that way as Philadelphia built its first lead of the game, 2-1, on Schenn’s 18th goal of the season.

Chris Porter was attempting to pass the puck through the neutral zone, moving it ahead to teammate Ryan Reaves. But Simmonds intercepted the dish and headed back the other way, eventually putting a shot on Miller’s pads.

The long rebound caromed to Schenn, who beat Miller easily for the go-ahead goal with 6:36 remaining in the second period.

“We made a mistake,” Hitchcock said. “We didn’t skate the puck out. So it was the difference in the hockey game.”

The Blues couldn’t catch up in the third period, despite several chances.

“I think overall, it’s not a bad game for us ... obviously better than Chicago,” defenseman Alex Pietrangelo said. “The goals we gave up — breakdowns in our own end — I think we’ve got to find ways when someone makes a mistake to pick them up.”

Added Backes: “(The Flyers) seem to have hit that playoff stride already and that’s something that we’re striving to get to, so that we’re playing every play like it could be the difference in the game or not.”

Jeremy Rutherford is the lead Blues beat writer for the St. Louis Post-Dispatch.