TORONTO — With a runner at third and three runs already home in the eighth inning Saturday, John Farrell made an aggressive move. He brought Craig Kimbrel in the game early.

Farrell’s reasoning: Kimbrel could get a couple of strikeouts to help the Red Sox hold their 8-7 lead, and then he could mow down the Blue Jays in the ninth.

Farrell said he wasn’t going to use Koji Uehara, who gave up Josh Donaldson’s home run and lost Friday night’s game.

For a closer, pitching 1? innings is often a lot, but every so often it’s necessary. Kimbrel had only had two longer outings in his career, two-inning appearances in 2010 and 2011.

It started out according to plan as Kimbrel struck out Kevin Pillar. Jose Bautista had other plans and he stroked a single through an open hole between first and second to score the tying run.

Bautista’s hit was simply well-placed, as he stayed on a 98-mile-per-hour fastball.

It was a very good, aggressive move by Farrell. It should have worked. When David Ortiz hit a solo homer in the ninth to give Boston a 9-8 lead, Kimbrel had another chance.

Really, everything that could go wrong did go wrong, including Kimbrel’s inability to finish hitters with two-strike counts, perhaps going to his curveball a little too often.

There were a series of missteps from Christian Vazquez, starting earlier in the eighth when Junichi Tazawa threw a wild pitch that the catcher couldn’t keep in front of him, allowing Russell Martin to score Toronto’s seventh run.

It was the ninth where things really fell apart.

With two outs, Kimbrel had Justin Smoak 0 and 2, then left a curveball up.

“I left it up and he drove it,’’ Kimbrel said. “I was trying to get it down, but not necessarily bouncing it.’’

Smoak came out of the game for pinch runner Ezequiel Carrera. He broke for second and Vazquez, known for his arm, made a poor throw that tailed off to the right and into the outfield, allowing Carrera to advance to third base. Vazquez said he doesn’t know why the ball tailed like that, but “if I had thrown to the base we would have had him.’’

Kimbrel left a 2-and-2 pitch too far over the plate, Martin stroked a double, and Carrera scored from third. Martin has been struggling all season. He should be one of Toronto’s easier outs, but that tied the game.

With Devon Travis batting, Kimbrel unloaded a wild pitch. Vazquez couldn’t find it, and Martin went to third.

“I thought it was in front of me, but it was behind me,’’ Vazquez said.

And then, well, another poor play. Third baseman Travis Shaw made a nice backhanded stop of Travis’s grounder down the line, but his throw was slightly to the home side of the bag and Hanley Ramirez couldn’t come up with it. The ball hit off Ramirez’s glove while the winning run scored. It was a close play, but Travis would have been out if Ramirez had caught the ball.

The Red Sox were one pitch away from winning a few times. It just wasn’t meant to be.

Farrell said Ramirez makes that play all the time. But he didn’t on this day. Ramirez couldn’t explain why he had trouble scooping the throw. Dustin Pedroia reasoned that the throw was going into the runner and he’s seen Gold Glovers not be able to make that play.

“That’s not the reason we lost the game,’’ Pedroia said.

Maybe not. But a series of slip-ups by Kimbrel, Vazquez, and Ramirez certainly led to an absolutely frustrating day of baseball. The Red Sox don’t usually make those mistakes. As Farrell pointed out, “We clearly didn’t execute when we had the chance.’’

Kimbrel, who turned 28 on Saturday, has probably enjoyed better birthdays. He had five days off between appearances and he wound up throwing 39 pitches, the most in his career for a single game. Farrell figured he could lean on him a bit more than usual and identified the precise moment in the game when he needed to stop Toronto’s momentum.

Asked about coming in with one out in the eighth and pitching on extended rest, Kimbrel said, “My job is to go out there to pitch, whether I have one day or two days or three. I’ve done it a few times. Coming in the extra inning sometimes it’s tough to get going. But the key is to attack the first hitter and get him out.’’

Which he did.

It’s always tough to lose games like these to a divisional rival. Toronto’s offense has been down all season, but it revived Saturday with a team-boosting walkoff win. The Red Sox don’t want to give the Blue Jays these types of wins and awaken a sleeping giant.

“It was a good game. We did a lot of good things,’’ the ever-optimistic Pedroia said.

The Sox were in “turn-the-page mode’’ and they felt good about wrapping things up here with David Price facing his old team Sunday.

The Red Sox haven’t given away many games this season. But they gave this one away. They had an 8-4 lead they couldn’t hold. It was unusual for Tommy Layne and Tazawa not to be able to do their jobs. That resulted in Farrell’s bold decision to skip Uehara and bring on Kimbrel for the kill.

But the Red Sox suffered self-inflicted wounds, despite the manager making the right decision.

Nick Cafardo can be reached at cafardo@globe.com. Follow him on Twitter @nickcafardo.