PHILADELPHIA -- The Philadelphia Flyers have gone from a team fighting for a playoff spot to one of the NHL's most dangerous contenders.
Jakub Voracek and Wayne Simmonds added goals in the third period, and Steve Mason made 32 saves to help Philadelphia improve to 12-2-1 in its last 15 games and maintain its hold on second place in the Metropolitan Division.
"I think we showed the league we can play with everyone and we can beat everybody," Voracek said. "It's going to give us some more confidence."
The Blues clinched a playoff berth despite the loss, the first Western Conference team to do so, as a result of Phoenix's 4-2 loss to Boston later Saturday.
St. Louis' Jaden Schwartz opened the scoring 6:23 into the game, finishing a 2-on-1, short-handed opportunity after taking a feed from Kevin Shattenkirk. Schwartz's wrist shot from close range went under Mason's glove.
The Blues again missed a chance to secure a playoff spot. One point would have made St. Louis the first Western club to qualify for the postseason.
Ryan Miller made only 15 saves and lost for the second time since being acquired by the Blues from Buffalo on Feb. 28. Miller was beaten 4-0 by Chicago on Wednesday in a game in which he was pulled after allowing four goals on 27 shots. He is 7-2-1 with St. Louis.
The Blues went 0-for-7 on the power play.
"Our level of determination in the offensive zone isn't what it's going to need to be to beat great goaltending," St. Louis coach Ken Hitchcock said. "We're going to have to find a way to get to a much higher level of compete in the offensive zone."
The Flyers dominated the second period when they erased a 1-0 deficit. Hartnell tied it 57 seconds in when he finished from right in front of the crease after a cross-ice pass from Voracek.
Miller appeared to try to stop the pass and was caught slightly out of position. Hartnell fired a wrister high into the open side of the net.
Schenn put Philadelphia ahead 2-1 when he scored off a rebound with 6:36 left in the period.
Simmonds took the initial shot after receiving a pass from Schenn. The rebound went right to Schenn, who put a backhander high over the sprawling goalie.
"(Simmonds) hit me in a good spot trying to go through my arm, and it pops up (to Schenn)," Miller said.
Mason preserved Philadelphia's one-goal lead with a pair of strong saves on Derek Roy with nine minutes remaining during a power play. Schwartz took the initial shot, and the rebound went to Roy, who was stopped by Mason's pads on his first attempt and the goalie's glove on the second.
"I was able to reach back and keep swatting at it," Mason said. "Saves that needed to be made."
Voracek provided a cushion when he beat Miller high to the stick side with 4:19 left. Hartnell stole the puck along the boards, fed it into the right circle to Claude Giroux, who passed it the open Voracek.
"We're really playing like a team right now and that's why we're successful. It really is," Flyers coach Craig Berube said. "We're coming. Our team is getting to where we need to get to to be successful."
Simmonds sealed Philadelphia's latest win when he scored into an empty net with 2:54 remaining.
"We're proving we're a good hockey team," Mason said. "We're beating the teams that, come playoff time, you're going to have go through to get to the ultimate goal."
Downie had his head turned when he skated into Berglund near the boards at center ice. Downie missed four games this season after sustaining a concussion during a fight on Nov. 2. The Flyers said he would be re-evaluated on Sunday.
Giroux had four of Philadelphia's 10 penalties. His eight penalty minutes matched one-quarter of the total (32) he had this season before Saturday.
St. Louis LW Magnus Paajarvi returned after missing three games because of an upper-body injury. The Blues remained without D Jordan Leopold (ankle) and RW Vladimir Tarasenko (hand). ... It was the first meeting between the teams since Oct. 22, 2011, when the Blues won 4-2 in Philadelphia. They will meet again on April 1 in St. Louis. ... After playing with a plain white mask in his first nine games with St. Louis, Miller unveiled a music-themed mask on Saturday. ... Blues RW T.J. Oshie, who entered with a team-best 54 points, went to the locker room with 11 minutes remaining after blocking a slap shot from Simmonds but later returned. . The Flyers announced after the game that LW Michael Raffl signed a multiyear contract extension.