Addison Barger blasted a towering grand slam as the Toronto Blue Jays thrashed the defending champion Los Angeles Dodgers 11-4 to take a 1-0 lead in Major League Baseball's World Series.

Barger's 126-metre blast to centre field at Toronto's Rogers Centre was the highlight of a spectacular nine-run sixth inning on Friday by the Blue Jays, playing in their first World Series in 32 years.

The win gives Toronto a precious early lead in the best-of-seven series, and they will look to double their advantage with victory in game two in Toronto on Saturday.

The Dodgers, bidding to become the first team in a quarter of a century to win back-to-back World Series, had made a smooth start, with Enrique Hernandez and Will Smith driving in early runs off Blue Jays starter Trey Yesavage to open up a 2-0 lead.

But the star-studded champions -- the most expensively assembled team in baseball -- were unable to build on their early lead despite getting the better of Yesavage.

Instead it was Toronto -- who have now won 50 games this season after trailing -- who wrestled their way back into contention with Dodgers pitcher Blake Snell unable to produce his most dominant form from the mound.

Toronto drew level in the fourth inning after catcher Alejandro Kirk singled into right field to get on base, and when Daulton Varsho crushed a 423-foot shot to centre-field, the game was tied.

Toronto's deep and disciplined batting line-up continued to cause problems for Snell, who was knocked out of the game in the sixth inning after loading the bases with no outs.

Snell gave up eights hits across five innings with five earned runs.

The Blue Jays then ruthlessly pounced on Dodgers reliever Emmet Sheehan to pull clear, with a single from Ernie Clement scoring Bo Bichette to give Toronto a 3-2 lead.

Nathan Lukes then drew a bases-loaded walk to give the Blue Jays a 4-2 lead with no outs before Andres Gimenez singled to make it 5-2.

Dodgers manager Dave Roberts replaced Sheehan with reliever Anthony Banda, but the Blue Jays continued to pile on.

Barger's grand slam made it 9-2 and then Kirk tacked on a two-run homer to put the Blue Jays 11-2 up as a sold-out Rogers Centre crowd erupted in delight.

The Dodgers' Japanese superstar Shohei Ohtani scored a two-run home run in the top of the seventh inning to cut the Blue Jays' lead to 11-4, but it never looked like being anything other than a consolation shot before Toronto closed out the win.

After Saturday's game two, the series will head to Los Angeles for games three, four and five on Monday, Tuesday and Wednesday.

Games six and seven, if needed, will take place in Toronto. (AFP)