PHILADELPHIA -- Michael Frolik scored 1:18 into overtime, and Sean Monahan had his first NHL hat trick to help the Calgary Flames defeat the Philadelphia Flyers 5-4 at Wells Fargo Center on Saturday.
Frolik beat Brian Elliott from the slot to help the Flames (11-8-0) to their sixth win in their past eight games.
Monahan had three power-play goals and an assist. He became the second player in Atlanta/Calgary history to score three power-play goals in one period (Claude St. Sauveur; Dec. 19, 1975 vs. New York Rangers).
[WATCH: All Flames vs. Flyers highlights]
Johnny Gaudreau, who grew up in southern New Jersey, had a goal and two assists to extend his point streak to an NHL career-high nine games (seven goals, 10 assists).
"Johnny found me a couple times there, and, I mean, he's from here, he's got a lot of people here, so I'm going to put the puck in the net for him," Monahan said. "It's nice, that hat trick means a lot to me."
Video: CGY@PHI: Gaudreau quiets crowd on breakaway goal
The Flames trailed 3-1 in the first period. The comeback victory came three days after the Flames began a six-game trip with an 8-2 loss to the Detroit Red Wings.
"It looked like it was going to be a long night, but we turned it around in the locker room between the first and second (periods)," said Gaudreau, who has a goal in five straight games.
Mike Smith made 35 saves for the Flames after missing one game with an upper-body injury.
"I think as the game went on, I got more comfortable," he said.
Brandon Manning, Sean Couturier, Ivan Provorov and Nolan Patrick scored for the Flyers (8-8-4), who have lost four straight games.
Elliott made 26 saves; he played for the Flames last season before signing a two-year contract with the Flyers this offseason.
"We put ourselves in a good position and we take too many penalties there in the second period," Elliott said.
Monahan scored three times in the second period, tying the game 3-3 with his second goal at 9:51. His third goal at 14:56, 11th of the season, made it 4-4 after Patrick scored 54 seconds earlier to give the Flyers a 4-3 lead.
Calgary coach Glen Gulutzan said he was surprised Monahan didn't already have a hat trick.
"That just goes to show you he's a consistent scorer," Gulutzan said. "He's not surviving on the big games all the time. Good for him. I've coached some good players and he really has a nose for the net."
The Flames went 3-for-5 on the power play. The Flyers took four penalties in the second period, including a bench minor for complaining to the officials.
"We got the penalties. We probably deserved them," Couturier said." "You've got to control what you can control, and it's definitely not yapping at the ref that's going to help us."
Video: CGY@PHI: Elliott reaches for solid glove save
The Flames hit the post twice in the third period before Frolik's fourth goal of the season.
Patrick's backhand rebound was the first goal at home for the No. 2 pick in the 2017 NHL Draft, in his second game after missing nine with an upper-body injury.
Couturier's rebound goal at 13:22 of the first period which gave the Flyers a 2-1 lead was the fifth power-play goal allowed in two games for the Flames, who entered play Saturday with the NHL's worst penalty kill (70.8 percent).
Video: CGY@PHI: Couturier slams home rebound for PPG
The Flames killed a penalty in the final 2:01 of the third period.
"I think that's going to help our confidence moving forward," Gulutzan said.
Goal of the game
Frolik's goal 1:18 into overtime.
Video: CGY@PHI: Backlund sets up Frolik for overtime winner
Save of the game
Smith on Patrick's shot at 5:54 of the second period.
Video: CGY@PHI: Smith stretches for right pad save
Highlight of the game
Monahan's third goal at 14:56 of the second period.
Video: CGY@PHI: Monahan completes hat trick of PPGs
They said it
"You never know with these afternoon games. From my experience, they've always been a little wild. I thought this game was good for the fans, hard on the coaches." -- Flames coach Glen Gulutzan
"Just little breakdowns. They're a good team and they made us pay on the penalty kill." -- Flyers goalie Brian Elliott
Need to know
Flyers forward Jordan Weal (upper body) didn't play, and defenseman Andrew MacDonald (lower body) missed his 12th straight game. … Frolik replaced forward Matthew Tkachuk, who served a one-game suspension for unsportmanlike conduct against the Red Wings, on the second line. ... Flyers defenseman Radko Gudas, who will have a phone hearing with the Department of Player Safety on Sunday, didn't play. Gudas slashed Winnipeg Jets forward Mathieu Perrault on the head Thursday.
Flames: At the Washington Capitals on Monday (7 p.m. ET; TVA Sports, NBCSWA+, SNW, NHL.TV)
Flyers: Host the Vancouver Canucks on Tuesday (7 p.m. ET; SNE, SNO, SNP, NBCSP, NHL.TV)
Video: Monahan has power-play hat trick in Flames' OT win