TORONTO -- The Toronto Maple Leafs got the first goal of the game on a deflection late in the first period and once again the Calgary Flames were in the familiar position of trying to catch up.

Instead of catching up, the Flames fell farther behind and the Maple Leafs claimed a 4-0 win led by two goals from Nazem Kadri, including the 100th of his career, and a shutout by Frederik Andersen.

Andersen made 26 saves to post his second shutout of the season and the eighth of his career.

The Flames have allowed the first goal in eight straight games, winning only two of them.

Mitch Marner and Zach Hyman also scored for the Maple Leafs (22-14-9), who had lost their two previous games. Marner added an assist and Nikita Zaitsev had two assists.

"We came in and we played the way we wanted to," Marner said. "Obviously, we got our power play back on track, which is nice. We really got a lot of scoring chances off of it, which I think built a lot of confidence for us going into Detroit (on Wednesday)."

"The frustration alleviates itself when you get some goals," Flames coach Glen Gulutzan said. "We didn't capitalize. The guys are squeezing a little bit. You just have to keep putting pucks at the net and bodies.

"If you're doing the right things, they'll start to go in. If we keep doing the right things, things will turn around."

Brian Elliott made 24 saves for the Flames (24-23-3), who have lost three games in a row.

"It's not the mindset when you get there (behind)," Elliott said. "It's just not getting there in the first place. That's what we have to challenge ourselves to do."

The Maple Leafs built a 3-0 lead through two periods and added to it early in the third period.

Kadri scored his second goal of the game and 20th of the season on a power play at 2:21 of the third. Calgary's Alex Chiasson was off for roughing when the goal was scored.

"Now we're starting to get more familiar with playing with leads and understanding how to play with them," Kadri said. "Again, we had to generate some energy in the building and no better way than to score a couple of goals first.

"It's exciting (to score No. 100). It's exciting to be able to share them with my teammates. Obviously, I've put in a lot of hard work, but at the end of the day, the only reason I care about that is because it helps our team win.

"It doesn't really matter how it goes in or who scores as long as it's in the back of the net."

The Maple Leafs led 1-0 after the first period on Marner's 11th goal of the season, a tip-in of Zaitsev's shot from the right point at 18:59.

"If we don't let in that goal at the end of the first period, it's a different story," Elliott said, "a whole different game."

Marner said, "It kind of caught me by surprise but at the same time I know (Zaitsev) is going to get it to the net. I think it hit my one skate and bounced up and over his shoulder. It was kind of lucky, but at the same time it was nice by Nikita."

Kadri scored his first goal of the game and 100th of his career on a shot from the top edge of the left faceoff circle at 7:00 of the second period to give Toronto a 2-0 lead. William Nylander earned the assist.

The Leafs took a 3-0 lead on a short-handed goal by Hyman at 16:55 of the second period. Elliott made the initial save on Hyman, who knocked the puck into the net for his seventh goal of the season when the goaltender failed to cover the puck.

Nylander was serving a hooking penalty when the goal was scored.

"We have to be better with our starts," Calgary left winger Johnny Gaudreau said. "We keeping saying that and we've got to do that. I think we need to find a way to score on the power play."

Gaudreau was shaken up by a check from Toronto's Leo Komarov at 12:36 of the second period and left the ice to be tested for a possible concussion. He cleared the test and returned to play.

"I feel fine. It's part of hockey. You get hit every once in a while," he said.

NOTES: Toronto D Morgan Rielly (lower-body injury) missed his third straight game Monday after being injured in the first period of last Tuesday's win against the Buffalo Sabres. He is listed as day-to-day. ... Calgary D Brett Kulak played in his first NHL game since Nov. 27. He had been a healthy scratch since being recalled from the AHL's Stockton on Jan. 9. ... The Flames defeated the Maple Leafs 3-0 on Nov. 30 at the Scotiabank Saddledome with G Chad Johnson earning the shutout. ... The Maple Leafs open a six-game road trip Wednesday with a game against the Detroit Red Wings. ... The Flames visit the Montreal Canadiens on Tuesday for a game at the Bell Centre, the second of three straight games on the road.