ST. LOUIS - The "restart" of the Flyers' season had some sloppy moments Wednesday at the Scottrade Center.

The passing wasn't sharp, there were too many giveaways in their own zone, and the offense looked out of sync for long stretches. Oh, and Steve Mason couldn't make a key save in a Blues-dominated third period.

All contributed to the Flyers' 6-3 loss to the St. Louis Blues.

Former Flyer Scottie Upshall and David Perron scored on deflections 80 seconds apart in the third period, putting the Blues in front, 4-3. Robby Fabbri beat Mason to the short side with 4 minutes, 59 seconds left to make it 5-3.

Fabbri's goal, his second of the night, gave St. Louis three goals on three third-period shots.

Clearing bodies in front of Mason "obviously" was a problem, Flyers coach Dave Hakstol said. "They got two tipped goals back-to-back on us," he said. "We have to get into those guys a little better."

With 2:56 to go, Fabbri completed his first career hat trick with an empty-net goal.

Upshall scored his first goal in the last 19 games, tipping in Joel Edmundson's shot with 12:47 to go and giving St. Louis a 4-3 lead.

"Tonight, we wanted too easy of a night. We wanted to play too easy of a game," Hakstol said. "We have to be better and we'll address that. We're not going into easy places to play on the rest of this road trip. We have to sort it out and get back to work."

The Flyers play two other big, physical teams on the trip, facing St. Jose on Friday and Anaheim on Sunday.

The Flyers had taken a brief 3-2 lead when Brayden Schenn, converting a Shayne Gostisbehere pass, ended the team's 0-for-17 power-play funk with 15:47 left. That came 28 seconds after Schenn's power-play goal was disallowed because the referee blew the whistle, thinking the puck had been covered by goalie Carter Hutton.

Perron answered 1:40 after Schenn's 10th goal of the season, knotting the score at 3.

"We have to be better in our own end," Schenn said. "As a five-man group, we have to get in the shot lanes, box out forwards and not allow them to get tips."

"We left Mase hung out to dry," Gostisbehere said.

The Flyers, thanks to an 11-2-1 run before the Christmas break, entered the night holding the Eastern Conference's second wild-card spot, seven points ahead of Carolina. The Hurricanes had three games in hand, however.

"We're in the middle of the battle," Hakstol said before the game. "It's what we do from here on in" that counts. "We're in a decent spot and we just have to keep building, keep getting better."

The Flyers generated just nine shots over the first two periods. Fortunately for them, two of the shots got past backup Blues goalie Hutton, who briefly was with the Flyers earlier in his career.

Nick Cousins' first goal in 17 games - a deflection of Ivan Provorov's shot seconds after the Flyers' first power play expired - tied the score at 2 with 15:28 left in the second period.

Playing with discipline was a key ingredient during the Flyers' recent 10-game winning streak. In that span, they had 45 power plays compared to their opponents' 28.

But the Flyers played out-of-control hockey in a sloppy 4-0 loss to New Jersey in their last game before the Christmas break, giving the Devils six power plays and allowing them to score on two of them.

The trend continued in Wednesday's opening period. Penalties taken by Claude Giroux (holding) and Roman Lyubimov (hooking) led to power-play goals by Kevin Shattenkirk and Fabbri, respectively, giving St. Louis a 2-1 lead.

Shattenkirk whipped a shot from above the right circle after taking a drop pass from Alexander Steen with 4:59 left in the first. Mason misplayed the puck earlier in the sequence, enabling St. Louis to keep the play alive.

With 11.7 seconds remaining in the period, a bad line change allowed defenseman Alex Pietrangelo to split the defense and go in alone on Mason. The goalie made the save, but Colton Parayko picked up the loose puck and fed Fabbri, who fired a shot from the high slot past a screened Mason.

Earlier, the Flyers had taken a 1-0 lead 3:25 into the game, scoring on one of their best passing plays of the season. Schenn found Travis Konecny (two assists), who threaded a pass in front to Wayne Simmonds for a tap in. Tic-tac-toe.

But the team's artistry was done for the night.