Bichette hit his first HR of the season as the Blue Jays beat the Mariners

Bichette launched a slider off Seattle starter George Kirby (1-2) that traveled about 431 feet. The Blue Jays (6-6) scored two more runs in the fourth inning.

Bassitt, meanwhile, threw 6 2/3 solid innings with his only blemish on Dominic Canzon's solo homer in the seventh.

“His journey has been incredible,” Schneider said. “He was in total command.”

Blue Jays reliever Trevor Richards gave up two runs to Mitch Haniger in the eighth. Chad Green recorded four strikeouts in his second save.

The Mariners (4-8) managed six hits.

“We're not playing great baseball,” Seattle manager Scott Servais said. “It was a frustrating night. It was not a good trip. The beginning of this season was not good.”

The Blue Jays have lost two series and split the other in their 10-game season-opening road trip. Toronto will look to end a three-game sweep of the Mariners on Wednesday afternoon.

Bassitt (1-2) was one of Toronto's most consistent pitchers last season, with a 16-8 record and a 3.60 earned run average over 200 innings. But he got off to a slow start this year and struggled early with some control issues against the Mariners.

The right-hander issued a walk in each of the first three innings but survived without injury. Cavan Biggio and Bichette helped complete a 4-6-3 double play to finish third.

Daulton Warshaw singled in the bottom half and took second base when Kirby was called out for a separation violation. George Springer fouled out on eight pitches before driving in his teammate with a single.

“He fought his ass off and then passed,” Schneider said. “George is a professional. I think his at-bats are really underrated right now.”

Vladimir Guerrero Jr. reached when he chased down Springer from second base and scored Bichette's first homer of the season. The explosion hit the 200-level seating in Toronto.

“Obviously, when I'm going well, I tend to hit the ball hard,” Bichette said. “Really (it's about) hitting every pitch.”

In the fourth inning, Keener-Falefa drove in Biggio with an RBI double and later scored on Springer's RBI single.

Former Blue Jays right-hander Trent Thornton pitched a single for Seattle in the fifth. Kirby allowed eight hits and five earned runs with three hits.

“I thought I was a little overmatched in the zone tonight,” Kirby said. “I just didn't expand as much as I should have.”

Canzone's homer was his third of the season, and Haniger's blast off a foul screen in left was his second of the year.

Bassitt allowed five hits, one run and four walks. He had eight strikeouts and lowered his ERA from 7.71 to 5.06.

“This line-up gave me a lot of trouble, so I knew I had to do something off-script,” he said. “I messed myself up a bit.”

The crowd was 31,310, after more than 40,000 opened the house the night before.

The game took two hours and 53 minutes.