Grabovski has six goals and two assists in the last four games, teaming with Hagman and Nikolai Kulemin to form a nice line. Grabovski had three goals in 27 career games with Montreal over the last two seasons and has seven in 15 for the Maple Leafs, who acquired him in a trade over the summer.
"He's been our best player for two weeks," coach Ron Wilson said. "He's been a dominant player. That's why he's got seven goals now."
Grabovski was gracious when asked about his time in Montreal after Saturday's game, but Hagman said he was pretty fired up to prove something to his former team.
"For sure he wanted to show the coach and show the other players on the team that he is a good player," Hagman said. "I think that he did a pretty good job."
The Habs (8-2-2) were playing for the second straight night and weren't able to match the pace set by the speedy Leafs.
Van Ryn lay on the ice for several minutes with a cut on his forehead and is expected to miss a month.
"It was a dirty hit," Leafs forward Matt Stajan said. "It's something that can't happen in the game. Luckily, we made them pay."
The incident left Kostopoulos visibly shaken. He planned to give Van Ryn a call to apologize.
"I was trying to get in there, get a hit and get the puck," Kostopoulos said. "Like I said, I didn't anticipate him turning and I couldn't stop myself. And I hope he's all right."
The Maple Leafs weren't able to get much going during the ensuing five-minute power play but Hagman converted the only good scoring opportunity they had. Grabovski made a nifty move to get around defenseman Andrei Markov before feeding Hagman at the side of the net for a goal at 8:12.
"He's playing well," Montreal coach Guy Carbonneau said of Grabovski. "Good for him."
The lead held until a wild second period that featured each team score three times.
Grabovski ripped a quick shot by former teammate Carey Price to make it 2-0 at 1:48 but was in the penalty box for goaltender interference when Lang scored three minutes later.
Plekanec's power-play goal at 9:59 tied it and drew a loud ovation from the large group of Habs fans that were among the 19,512 in attendance at Air Canada Centre.
Hagman and Koivu then traded quick goals before Antropov put the Leafs up 4-3 at 16:27. With Price out of position, Antropov took four whacks at the puck in a scrum before finally getting it past Habs defenseman Mike Komisarek.
That goal gave the Leafs a lead heading into the third period for just the fourth time in 15 games this season. They had no trouble holding on.
Toronto now heads out for a tour of Western Canada that includes stops in Calgary, Edmonton and Vancouver. There was no better send-off than a win over the rival Canadiens.
"We really wanted that game," Stajan said. "That's how we've got to play every game, come out with an edge and really take it to them. Even when they came back there, we never gave up.
"You know, we're proving to everybody -- we know in here that we can play with any team in this league. There's no doubt about it, that's one of the best teams in the league."
Former Leaf and World War II veteran Gaye Stewart read the poem "In Flanders Fields" before the game. ... Since the NHL lockout, each team has won 13 games in the series. The total number of goals in those games? Montreal 87, Toronto 87. ... The Habs scratched Roman Hamrlik, Mathieu Dandenault and Steve Begin. ... Jiri Tlusty replaced John Mitchell (shoulder) in Toronto's lineup. ... Jonas Frogren, Anton Stralman and Ryan Hollweg sat out for the Maple Leafs.