Baltimore had won the first game, 4-1. The loss in the nightcap left the Orioles 1 1/2 games behind New York in the American League East after the Yankees topped the Twins, 6-3. The O's remained in first place in the AL Wild Card standings.
Wei-Yin Chen started for the Orioles and ran into early problems. He gave up a two-run homer to Edwin Encarnacion in the first, plus two more runs in the second to put the Blue Jays in front, 4-0. Chen gave up five runs in five-plus innings.
"After the first batter in the first inning, I walked a guy. I started feeling like, 'Wow. This is not the day for me,'" Chen said through an interpreter. "I tried to fight, fight through it. It definitely was not my day, things went a different direction."
The Orioles repeatedly tried to battle back, but couldn't quite make it. They had numerous chances. They left the bases loaded in the second and fifth, stranded two in the sixth and missed on two chances to tie the game in that inning. Overall, the O's left 10 on base.
"We had our opportunities," manager Buck Showalter said. "Had some good people up. A lot of good at-bats to set that up to get to that point. There's two parts to that equation. One is setting up the potential and the other is trying to carry it through."
Baltimore just couldn't do it. And that's where the momentum swing changed the game.
Toronto held a 4-3 lead after five innings before Moises Sierra's solo homer to open the sixth gave the Jays a two-run lead. Showalter replaced Chen with Arrieta after the Jays put runners on first and third with none out. The right-hander fanned Anthony Gose, Brett Lawrie and pinch-hitter Colby Rasmus to send Oriole Park into a frenzy.
The cheers kept going when the Orioles loaded the bases with no outs in the bottom half. J.J. Hardy then lined a single to left to make it 5-4. But instead of being a two-run, game-tying hit, Teagarden had to hold at third as the ball was hit too hard.
Adam Jones then struck out with the bases loaded before Chris Davis hit a fly ball to medium left field. Gose caught it and made a perfect throw to the plate to nail Teagarden, end the inning and let the Blue Jays escape with a 5-4 lead.
Arrieta loaded the bases with no outs in the seventh, then retired the next two batters before Arencibia blasted his grand slam to left for a 9-4 edge. He finished 3-for-3 with five RBIs -- after coming into the game on a 2-for-36 skid in 10 games since coming off the disabled list.
"He left a pitch up, and I was able to hit it out of the park," Arencibia said.
Ricky Romero (9-14) lasted five-plus innings for Toronto and ended his personal 13-game losing streak. He gave up four runs on eight hits as the Orioles hit him hard at times, but the left-hander escaped.
"It's a game of momentum," Davis said. "They did a good job of keeping after us. I thought we battled against Ricky, but you've got to give them credit. I thought we gave ourselves a chance to win the second game, but obviously the home run by Arencibia was a crushing blow."
Nate McLouth went 1-for-2 with a homer and two walks. Hardy, Davis, Robert Andino and Jones added two hits apiece. Jones finished the doubleheader 6-for-9 and has hit in 19 of 23 games this month.
The Orioles have eight games left. They aren't worrying about the Yankees winning. Jones said there's not much they can do about it.
"We have to take care of ourselves," Jones said. "We're not playing the Yankees any more the rest of the season. We just have to take care of ourselves."
Sweeping this doubleheader is what the Orioles would have liked to do, but winning two games in one day is a tall task. Steve Johnson and Jones helped Baltimore win the opener without much trouble. The nightcap, however, wound up being a game where the Orioles needed to keep battling and fighting.
"These are the type of games you find out what your team is made of," Davis said. "We've talked about all the positive things we've done all year and how we're a very resilient team and how we've played well in extra innings. These next few games are really going to test us a team. I'm looking forward to it."