BALTIMORE — The Orioles have a belief they can win any game.

They’ve said it. They’ve shown it. But at the same time, the odds were well against them as they entered the bottom of the ninth inning at Camden Yards on Saturday evening facing a four-run deficit against the Blue Jays.

At that point, Baltimore’s win probability was 1.9% (per Baseball Savant). It dropped to 0.7% when Samuel Basallo struck out to open the frame against Toronto right-hander Jeff Hoffman.

Yet, the O’s still believed — and it turned out they were right to do so.

A five-run rally in the bottom of the ninth completed the Orioles’ improbable comeback attempt, as Pete Alonso knocked a walk-off RBI single to lift them to an unbelievable 6-5 victory. It was the first time Baltimore won a game in which it trailed by at least four in the ninth since June 7, 2017, when it recorded a 9-6, 11-inning victory over Pittsburgh.

Why did the O’s think they could do it?

“There’s never a doubt. I mean, we’ve done it a few times this year,” Alonso said. “Because we’ve done it, it’s like, ‘Hey, we’re never out of it.’ The talent and just the personnel we have, we all believe in each other. We know that’s definitely capable and within reach.”

Alonso also could have said the Orioles have done it a few times this week. Saturday marked their third walk-off win in seven days, as Colton Cowser hit a game-ending three-run homer on Sunday (a 5-3 victory over Detroit in the opener of a doubleheader) and followed it with a walk-off two-run homer on Monday (a 9-7, 13-inning win vs. Tampa Bay).

So, here’s the better question — how did the O’s do it this time, with seemingly less of a chance to do so?

It began when Hoffman hit Coby Mayo with a 1-1 sinker with one out. Sure, Baltimore only had one runner on base. But Mayo took the pitch to the left elbow and didn’t even flinch.

“The huge momentum was Coby wearing one for the boys right there,” Alonso said. “He took it like a man, and that kind of fired us up in the dugout.”

From there, it was one quality at-bat after another.

Leody Taveras hit an RBI triple to right field. Jackson Holliday followed with an RBI single to right. Cowser hit a double to right, and Taylor Ward drew a walk to load the bases when the Orioles still trailed, 5-3.

Gunnar Henderson drew a bases-loaded walk to end Hoffman’s day. And then, the Blue Jays turned to right-hander Connor Seabold, who immediately walked Adley Rutschman as the game became tied at 5. (The O’s 11 walks marked their most in a game since July 27, 2005.)

“Everyone was in the dugout saying, ‘Get the tying run up, one at-bat at a time.’ We don’t waver,” manager Craig Albernaz said. “The guys in the clubhouse, they’re outstanding, they don’t waver. But also, to say that in the dugout and then go out there and be really disciplined in the box — especially when the crowd’s going nuts and everyone wants to be the hero — being able to be selfless, take your walk and pass it to the next guy, that was fun to watch.”

It all set the stage for Alonso to be the hero. And the 31-year-old slugger — who has already had some ups and downs during his first season in Baltimore — came up in a situation in which he’s struggled. The Polar Bear had fallen to 0-for-8 in bases-loaded spots this year after grounding into a 5-4-3 double play to end the third.

This time, Alonso came through. Toronto played its infield in, and Alonso connected on a 2-1 fastball from Seabold and punched it into right-center at an exit velocity of 104.4 mph for his first walk-off knock as an Oriole.

“To be able to get Pete up there, you know he’s going to put the ball in play and hit the ball hard,” Holliday said. “I felt pretty confident with him up there that we were going to win.”

Here’s how Statcast’s win probability changed as the bottom of the ninth unfolded:

Basallo’s strikeout: 0.7%
Mayo’s HBP: 1.8%
Taveras’ RBI triple: 5.5%
Holliday’s RBI single: 11.2%
Cowser’s double: 29.8%
Ward’s walk: 34%
Henderson’s RBI walk: 54.5%
Rutschman’s RBI walk: 83.7%
Alonso’s walk-off RBI single: 100%

The O’s (27-32) had dropped the first two games of the series against the Blue Jays after previously sweeping a three-game home set vs. the American League-best Rays.

After Saturday’s remarkable win, Baltimore will have an opportunity to split the four-game series vs. Toronto and finish its season-long 10-game homestand with a 7-3 mark — a positive swing that may have prevented the Orioles’ season from sinking before the end of May.

“Hopefully, we win tomorrow. When we win tomorrow, I think that’d be 7-3,” Alonso said with a smile. “If you play 10 games, you go 7-3, you’ll take that every time. If we can get the job done tomorrow, that’d be a great momentum starter for us as the year progresses.”