Larin was on the field for less than three minutes in a frenetic Group B opener that long looked like it would end in defeat for the co-host when he swivelled in the box and fired home the equaliser in the 78th minute to etch his name in history with the first Canadia FIFA World Cup goal on home soil.

"It was special for me. I was ready to come and help the team," Larin said. "I thought the goals would come. I score when Canada needs me, and always have done."

Bosnia went ahead in the 21st minute when Jovo Lukic steered home a flick-on from a corner for his first international goal, but Canada thundered forward and should have equalised through Richie Laryea in the 53rd, only for Bosnia's Sead Kolasinac to steer his shot off the crossbar miraculously and away to safety.

A packed Toronto Stadium along the shores of Lake Ontario is the smallest of the 16 venues for this year's FIFA World Cup but what it lacked in size was made up for in atmosphere as the sea of red supporters clapping and chanting "Ca-na-da" throughout provided a constant soundtrack to the game.

After falling behind, Canada continued to attack but despite creating plenty of chances lacked precision as Bosnia, which appeared to tire as the game wore on, dealt with a succession of crosses and looked to be heading for a narrow victory.

Larin had other ideas, however, when introduced in the 76th minute and made an immediate impact by firing home a deflected strike to equalise and send the home crowd into raptures.

"The subs came on and made a big difference. The tempo got higher, and we could see that they were fading," Canada coach Jesse Marsch said.

"So, I told them that we've got them now. It's time to put your foot on the jugular and go for the goal."

The result gave Canada a first FIFA World Cup point after six defeats from six matches across the 1986 and 2022 tournaments but left it short of the win it craved.

Jonathan David had a glorious chance to put Canada in front early on but the country's all-time leading scorer sent his well-struck shot straight at goalkeeper Nikola Vasilj.

After Lukic put the battle-tested Dragons on the board it was Canada that took over the contest.

Canada pressed for the rest of the half but was unable to establish much of a presence deep in the Bosnia half with almost every ball it sent into the area quickly cleared from danger.

The hosts nearly drew level at the start of the second period when Laryea went through on goal and his shot looked certain to head over the line until Kolasinac stepped in at the last moment to clear the ball via the bar.

With the game starting to open up, Bosnia nearly doubled its lead moments later when Ermedin Demirovic went through on goal but Maxime Crepeau, making his FIFA World Cup debut after missing the 2022 edition with a broken leg, made a crucial save.

That set the stage for newly-minted Southampton striker Larin, who blasted home a right-foot shot from the centre of the box in the 78th minute moments after entering the game.

"I'm just really proud of this group, in terms of, you know, we easily could have folded once we conceded that first one and let our heads drop," Canada right back Alistair Johnston said.

"But no, we came out in the second half with another level, and we reached it, we really took a hold of the game."

After the match, Bosnia's players stood in front of the goal and saluted their contingent of blue-clad fans, who filled two sections in the upper level and made their presence felt all afternoon with a steady drumbeat and lots of singing.

Bosnia will next turn its focus to a meeting with group favourite Switzerland on 19 June (AEST) in Los Angeles while Canada faces Qatar later that day in Vancouver.