TORONTO -- It’d been a while since the Blue Jays had experienced “one of those days.”

Riding a six-game winning streak and one win away from a perfect six-game homestand, Toronto watched a four-run lead turn into a 10-8 loss to the Mariners in 10 innings on Sunday afternoon at Rogers Centre.

It was a jarring momentum stopper, especially after the Blue Jays roared back from a 4-0 first-inning deficit and carried an 8-5 lead into the eighth. But this one looked weird from the start.

“Just one of those days,” starter Chris Bassitt said after the game. “The guys have been playing pretty well, [but] yeah, things happen. It’s baseball. I wish everything could go perfect, but it’s a beautiful game.”

The oddities began with Bassitt, who opened the game with back-to-back strikeouts before allowing a grand slam to newly promoted Taylor Trammell.

Bassitt -- and the rest of the Blue Jays’ infield -- thought he’d thrown strike three to Jarred Kelenic, the Mariners’ No. 3 hitter, to end the first frame. To the righty’s clear frustration, though, his 93 mph sinker at the bottom right of the zone was deemed a ball. Two pitches later, Kelenic took first base with a walk.

Bassitt also walked Cal Raleigh, then he hit Teoscar Hernández with a pitch to load the bases for Trammell, who put the Blue Jays in an early hole with one swing.

“It’s part of it,” Bassitt said of his first-inning frustration. “Umpiring is hard.”

The Blue Jays got two runs back on a Matt Chapman double in the home half of the first, while Bassitt regrouped in the dugout before going back out for the second.

From then on, he locked in, throwing four more scoreless frames and striking out seven Mariners hitters on 96 pitches (38 of them in the first).

“He was frustrated after that first [inning], but I think kind of bearing down and getting through five [was impressive],” said manager John Schneider. “You know, it sucks for him that the pitch count got where it did -- probably unnecessarily -- as well as the score. But yeah, I just can't say enough about his composure to get back in. That's kind of what he does.”

The Blue Jays’ offense also did what it does, grabbing the lead on a Bo Bichette three-run homer that traveled a Statcast-projected 460 feet and left his bat at 113 mph to give Toronto a 5-4 lead in the second. The club added three more in the following frame and it looked like it would cruise into a perfect homestand until the eighth.

That’s when the Blue Jays were hit with a case of “one of those days” again.

Toronto’s bullpen, which had allowed just one run in the previous five games, surrendered two in the eighth on a Raleigh homer to right-center field and one in the ninth on a J.P. Crawford single that tied things up at 9. Raleigh -- one of Seattle’s Wild Card heroes last year -- homered again in the 10th, a no-doubter to right off Zach Pop.

“Everyone's going to have a bad day,” said Schneider. “I think today [there were] missed spots and probably some pitch selection that could have been a little bit different. …

“They've been on such a roll, you know. It's not going to be perfect every single night. Today is just an example of that.”

The last out of the game came on a Vladimir Guerrero Jr. fly ball with runners on first and third, a situation that has gone the Blue Jays’ way many times before. But as fans at Rogers Centre held their breath, Kelenic secured the out at center, robbing Toronto of back-to-back extra-inning walk-off wins and of an unbeaten homestand.

Just like the good days, though, the weird ones don’t last forever. And the Blue Jays, who start a four-game set in Boston on Monday, have plenty to build upon amid a 7-3 stretch that included six games at home in which they outscored opponents by 18 runs (32-14).

“We had our chances today,” said Schneider. “We had our chances just like they did, but we didn't capitalize. But you look back and you really like the homestand, winning two out of three against these guys.

“You win the series and you keep moving on.”