BOSTON — Joe Biagini took the mound Sunday evening with a purpose.

Two nights earlier, he’d been tagged for three runs in a hard-luck inning that ended up deciding a game. Even though there was little in that inning he could have done differently—more on that later—he had still blown a lead in a very important game for his team and it still stung like hell. So, when his name was called in the bottom of the eighth inning Sunday with one on, one out, and a one-run lead in another extremely important game for his Toronto Blue Jays, Biagini was charged up.

He brought everything he had. Biagini touched 97-mph twice in the inning as he barraged Dustin Pedroia and Brock Holt with fastballs and cutters while the tying run stood on second base, getting Pedroia to ground out softly and Holt to swing over strike three. For Biagini, who has been the Blue Jays’ most quietly-crucial bullpen arm this season, it was just another pivotal, pressure-cooker moment in a season full of them.

"You can’t say enough about what Joe’s done," said Blue Jays manager John Gibbons, who puts him in those moments. "He’s established himself in the big leagues."

Biagini’s shutdown appearance Sunday couldn’t have gone more differently than how things played out two nights earlier. He started the seventh inning with his team up by two, and by the time the third out was made the Red Sox had scored four times. He took the loss—there’s no way around that. But a day after that dispiriting misstep, it was hard to find fault with Biagini’s performance.

"His job is to come in and get groundballs," Gibbons said, looking back on his club’s 5-3 loss in Friday’s series opener. "And, you know what, he came in there and he got groundballs. He forced contact. He wasn’t all over the place, walking guys and getting hammered. He pitched the way he normally does. It’s just—sometimes they find holes.

"He shouldn’t feel bad about it at all. I’m sure he does. But he shouldn’t."

Here’s how it went down. Red Sox outfielder Andrew Benintendi opened the inning with a double to right-centre field, going well below the zone to hit a Biagini curveball that nearly spiked in the dirt.

Then Pedroia chased another pitch well outside the zone, and nudged it about 10 feet in front of home plate. Russell Martin went after it, but the ball picked up plenty of condensation from the grass on a rainy Boston night, and the Blue Jays catcher sent a poorly gripped throw wide of first base.

"I saw the ball sitting right in front of home plate, and even from where I was I could see the glisten of the water on it," Biagini said. "I just thought to myself, ‘oh no.’"

The ball ended up beneath a tarp along the right field wall, which meant Benintendi scored and Pedroia went to second on a ball that didn’t make it to the pitcher’s mound.

A wild pitch on a changeup with absurd movement let Pedroia move to third. But after that, Biagini got two more groundballs, one from Brock Holt that went for an out, and one from Mookie Betts that got through a drawn-in infield for another run. Biagini left the game, and Brett Cecil gave up a home run to the very next batter, David Ortiz, which clinched the loss for Biagini and the Blue Jays.

That’s never good. The results are what they are. But when Biagini went back and watched the inning the next day with his coaches, he was hard pressed to find something he could have done differently.

"We looked pretty hard at it and there might have been a couple pitch selections that could have been different. But, really, I felt like I did a decent job of executing pitches," Biagini said. "I can’t say that I could have done too many things better. Certainly, in every game you pitch you can make better choices and perform better. But some of these things come down to just how the game goes. You have to be okay with it."

A rule-5 pick who had never pitched above double-A before this season, Biagini has been a tremendous surprise for the Blue Jays. His 67.2 innings pitched and 3.06 ERA trail only Roberto Osuna among qualified Blue Jays relievers. He’s been imperative in bridging the gap between Toronto’s starters and it’s late-game relievers, pitching two innings or more 13 times this season, and earning a 0.69 ERA in those appearances.

"Joe’s been tremendous all year," Gibbons said. "We didn’t know how good he was going to be. But he’s done a hell of a job for this team. And in some really key spots, too. He got us to this point. He’s been one of those guys."

He’s also made himself into a more complete pitcher as the year has gone on, introducing a cutter he learned during spring training, which gives Biagini five pitches to attack hitters with.

"It’s ended up being one of the bigger pitches for me the whole season," Biagini said. "I’m pretty happy with it."

Biagini has tried to learn a cutter for years, coming to spring training in 2014 and ’15 with variations of the pitch he had worked on all off-season, only to have all that work come undone. Either the grip was wrong or the arm angle was too high or his wrist control wasn’t there to locate it consistently.

This past off-season he went back to the drawing board, sitting down with his father, Rob, who pitched in the San Francisco Giants organization in the early 1980s. Rob spent hours going over video with Biagini and suggested his son needed to stop trying to invent a new pitch and simply modify one of his others.

Biagini started with his four-seam fastball grip and turned his wrist angle slightly, so he could throw the pitch like a fastball but still generate the cutting movement he was after. The wrist adjustment meant a slight sacrifice in velocity—his cutter generally sits in the 91-92 mph range, while his four-seamer sits 94-96—but it generated nasty, slider-like movement that hitters have thus far had trouble picking up.

"My dad’s helped me a ton throughout my career. He spends a lot of time with me, talking through stuff," Biagini says. "I was pretty frustrated the previous few years with not being able to learn it. I knew that it would be really nice to have something that moved like a cutter that didn’t have the big break of my curveball. I was trying all these things, but really, what I needed to do was simplify. Just that subtle wrist turn. You have to be really disciplined in order to throw it like a fastball and not do too much with it. But if you can do that, it’s pretty consistent."

Biagini now uses his cutter more than his four-seamer or his changeup. He still builds all of his offerings off of his two-seamer, including a wicked curveball that hitters are batting just .171 against this season. But the cutter has quickly become his second-most important pitch.

In the past, Biagini featured his changeup more often than he does now. But the right-hander has struggled with his feel for the pitch this year, sometimes struggling to locate it. That’s led to Biagini using it just six per cent of the time, but there have been situations where it’s been a very important weapon for him.

Take Friday night. Before the game got away from him in the seventh, Biagini entered in the bottom of the sixth and, after getting a groundout with his first pitch, left a fastball up to Xander Bogaerts, who laced it into the right field corner for a triple. With a runner on third and just one out, Biagini attacked Jackie Bradley Jr. with cutters, striking him out on four pitches before battling Red Sox catcher Sandy Leon to a 2-2 count.

At that point, Blue Jays catcher Russell Martin called for another cutter, which had worked so well against Bradley Jr., a left-handed hitter like Leon. But Biagini shook three times until Martin called for the first changeup of the inning. Biagini reached back and threw a pitch that travelled on the exact same plane as his cutter at a similar speed, but broke in a completely different direction.

Leon missed badly, ending the threat as Biagini preserved the two-run lead. When Martin came out to take an at-bat in the next inning, Leon looked up from behind the plate and told him it was quite a pitch. Martin told Leon, "I was thinking cutter, you were thinking cutter — I think Biagini was the only guy in the ballpark thinking changeup."

"I think what Russell called originally, the cutter, was probably the smarter pitch to go with," Biagini said. "He knows these hitters so well; he does a really good job of preparing. But I was thinking that since I had thrown so many cutters in the previous batters, I could maybe surprise him with that changeup. And I guess I did."

Biagini’s surprised a lot of people this season. But what was no surprise to his team was how he bounced back from a dispiriting inning Friday to get two crucial outs Sunday and help the Blue Jays clinch a wild-card spot. If Toronto gets past Baltimore in the wild-card game, Biagini will be an integral bullpen piece in the post-season, able to go multiple innings if need be or to enter a game with runners on and get big outs. He’s perhaps the unlikeliest important piece the Blue Jays have.

"For a guy who was a rule 5 pick coming out of double-A, never been a reliever," Gibbons said, "yeah, he’s made a name for himself this year."