The so-called third liners, playing mainly with Nick Paul on the other wing, piled on the goals as Canada defeated over-matched Slovakia 8-0 to open the tournament on Friday night.
Fabbri had two goals and an assist, while Petan had a goal and two helpers to lead the onslaught.
"Points are one thing, but the way the team played the whole game, staying level headed, sticking to our game, it was good to see and good to win the game," said Fabbri, a St. Louis Blues prospect.
"I get switched around once in a while, but to play with Nic Petan, he's such a special player. So skilled and he works really hard. It's easy just to feed off him."
A disappointing crowd of only 14,142 turned out to the Bell Centre, but those who stayed away missed a dominant performance from a Canadian side that looks strong and deep on attack.
Fabbri scored twice and Anthony Duclair had the other as Canada got three goals in a 4:17 span of the first period, then added four more in the second and another in the third while owning the puck and out-shooting Slovakia 34-12.
The Canadians will try to keep it going against Germany on Saturday.
"It helps with confidence and stuff like that, but the way we're thinking is that this game's over and done," said Petan. "A game like that, you think it's easy, but you're still working as hard as you can. It isn't like you're taking a step off the gas pedal. You're playing the right way."
Duclair, Max Domi, Jake Virtanen and Brayden Point each had a goal and an assist. Paul also scored, while Sam Reinhart and Madison Bowey had two assists each.
Zach Fucale, who was barely tested, got the shutout. Eric Comrie gets the start against Germany.
Coach Benoit Groulx was delighted to see goals from many sources, even if his top line of Connor McDavid, Curtis Lazar and Nick Ritchie was held off the scoresheet.
"It was nice to see the offence come from our third and fourth lines," said Groulx. "I really feel that with our speed up front, we were able to put them on their heels.
"Connor, Duclair, Reinhart, they have tremendous speed and it's tough to defend. And it's tough when you have Brayden Point who you can put on any line and he adjusts. We have offence on every line and it's up to us to find a way to bring it out, day in and day out."
The Germans will no doubt play a tighter checking game in the neutral zone.
Groulx said he doesn't fear complacency from his side, which is motivated by playing at home even if the rink wasn't filled to its 21,000-plus capacity.
Canada didn't know what to expect from Slovakia. At last year's tournament in Malmo, Sweden, they trailed the Slovaks 3-2 after two periods before storming back for a 5-3 win on two goals by Petan, one of seven players back this year.
Slovakia captain Martin Reway looked shell-shocked after the defeat.
"It's my third year here and we always played tight games with them," said Reway, a former Gatineau Olympique now playing in the Czech Republic. "We know they're good, but I told the guys we can play with them. But we didn't play well in the first two periods."
Slovakia faces Finland on Saturday.
To get it started, Fabbri finished a tic-tac-toe play with Reinhart and Duclair at 4:52, Duclair took a feed from Domi alone in front and put a slick move on Denis Godla at 8:12 and Fabbri got behind the defence to take Petan's pass and lift it over the Slovak goalie at 9:09.
Slovakia coach Ernest Bokros called a timeout and his team played managed to hold Canada off the rest of the period.
But Paul fought off a check to lift one in 6:54 into the second frame while Point one-timed Petan's pass in at 11:38. That prompted a goaltending change as Godla, who stopped 18 of 23 shots, was replaced by David Okolicany.
Domi beat him cleanly with a long wrist shot to the top corner on a solo rush at 16:14 and Petan walked out of the a corner with the teams each short a man and zipped one under the crossbar at 17:21.
The Slovaks had one dangerous flurry early in the first period that was held off by Fucale, who wasn't threatened again until he made a big stop on Peter Cehlarik five minutes into the third.
"I need to stay focused no matter how many shots I get, whether I get two or 50," said Fucale.
Notes — It was expected that Dillon Heatherington would be Canada's seventh defenceman, but it ended up with Samuel Morin skating sporadic shifts. . . The Slovaks got their third shot at 6:45 of the first frame and their fourth at 7:29 of the second. . . Canada opened last year's tournament with a 7-2 win over Germany.