George Springer blasted a three-run home run to end the Toronto Blue Jays' 32-year wait to return to the World Series on Monday, crushing the Seattle Mariners' dreams of a first ever appearance in Major League Baseball's championship finale.

Springer's seventh-inning 381-foot rocket into left field propelled the Blue Jays to a 4-3 game seven victory after the Mariners had taken a 3-1 lead at Toronto's Rogers Centre.

The Blue Jays will now face the defending champion Los Angeles Dodgers in a best-of-seven battle for the Fall Classic, with Game One set for Toronto on Friday.

It will be the Blue Jays first appearance in the World Series since the Canadian franchise won back-to-back titles in 1992 and 1993.

"I'm just so happy for our team, our city, our country," an elated Springer told Fox Sports television following the win. "This is such an unbelievable moment."

Springer had been forced to exit game five in Seattle last week after being hit on the kneecap but said he had fought through the pain barrier to help Toronto clinch victory in Monday's decider.

"It doesn't matter," Springer said of his sore knee. "I owe it to these fans, this city and this country to give them my all. So I'll take it."

The defeat was cruel on Seattle, who had dared to dream of the franchise's first ever trip to the World Series after doggedly pulling into a 3-1 lead with the finish line in sight in the seventh inning.

Seattle had got off to a solid start, with Josh Naylor's single to right field bringing home Julio Rodriguez for a 1-0 lead in the top of the first inning.

Toronto hit back immediately in the bottom of the inning, however, with centerfielder Daulton's single sending Springer scampering across home plate for 1-1.

A third inning home run from centerfielder Rodriguez followed by another towering homer from catcher Cal Raleigh in the fifth inning put the Mariners 3-1 up.

But Springer – a member of the Houston Astros 2017 World Series-winning team – stepped up in the seventh inning to catapult Toronto into the lead and into the Fall Classic. (AFP)