Eugenio Suárez hit a go-ahead grand slam after Cal Raleigh’s tying drive in a five-run eighth inning, giving the Seattle Mariners a 6-2 win over the Toronto Blue Jays and a 3-2 lead in the American League Championship Series.

Suárez also homered in the second inning for Seattle’s first run in the game on Friday.

The Mariners became the first home team to win in the series and moved within a victory of the first World Series trip for a franchise that started playing in 1977.

“For our fans, they’ve waiting a long time for this moment and we’re here to give it to them. We’re here to fight for a World Series,” Suárez said.

Game six is at Toronto on Sunday night.

Raleigh, a switch-hitting catcher who led the major leagues with 60 home runs during the regular season, was hitting right-handed for the first time in the series when he led off the eighth by pulling a 2-0 changeup from loser Brendon Little.

The drive rose 47 metres above the field on a high arc and had a 6.7-second hang time before it dropped over the left field wall at T-Mobile Park, 106 metres from the plate. Raleigh's fourth homer of the postseason tied the score 2-2.

“Obviously it was really high, so you never know in this building,” Raleigh said. “Luckily today the roof's closed.”

Jorge Polanco and Josh Naylor walked, and Seranthony Domínguez relieved and hit Randy Arozarena with a pitch.

Suárez fouled off a 2-2 fastball, then hit an opposite-field drive to right, and the ball landed several rows into the seats for his fourth slam this season.

“Obviously, this is the biggest home run of my career,” he said.

Suárez, who had put Seattle ahead in the second against Kevin Gausman, entered the game in a six-for-50 slump.

He was acquired from Arizona at the trade deadline, finished the regular season with 49 homers and has three in the playoffs.

“I’ve been waiting for this for a long time,” he said. “It’s been a while [since] I’ve had a game like this today. It was awesome being to hit that grand slam there to give the win to my team, to the fans. They’ve been here supporting us all year long.”

Seattle's Bryce Miller was pitching shutout ball when he was removed after allowing Addison Barger's leadoff single in the fifth, and George Springer hit an RBI double off Matt Brash.

Springer left in the seventh when he was hit on the right kneecap by a 153 kmh sinker from Bryan Woo.

“He’s got a right knee contusion. He had X-rays, which were negative, which is a good thing,” Blue Jays manager John Schneider said.

“George is about as tough as they come. I think he’ll have to really, really be hurting to not be in the lineup on Sunday.”

Toronto wasted many chances, going two for 11 with runners in scoring position. (AP)