While the Red Sox were having a miserable night in the Great White North, Rivera had his own issues. But with Andy Pettitte's 200th career victory and a 1 1/2-game deficit in the American League East on the line, Rivera struck out pinch-hitter Scott Moore with the bases loaded, finally preserving a 2-1 victory over the Orioles.
"He's going to bend," manager Joe Torre reflected. "He's not going to break."
That offhand phrase could be applied to the entire team, which has fought staggering odds to rally back from a dead-in-the-water, 14 1/2-game deficit on May 29 and can now begin to savor some of their efforts.
With a wide 5 1/2-game berth in the AL Wild Card race, New York's 13th consecutive playoff appearance may be a near-certainty, but the Yankees are still gunning for the division title.
Boston's evening was crushed in the eighth inning, when Jonathan Papelbon served up a grand slam to Toronto's Russ Adams, helping the Yankees move closer to the Red Sox -- 1 1/2 games back and one in the loss column -- than they've been since April 19.
"We've been playing good, you know?" Pettitte said. "I think that everyone in here felt like we're a good team. We knew it was a long season, but in the midst of looking at a deficit of 14 or so, you're like, 'My goodness.' But we knew if we kept playing and we stuck together, we'd be fine."
The troubled start was besieged with injuries, distractions and drama, and few would have imagined any scenario in which the Yankees could have 10 games remaining and still own a legitimate shot at securing the division.
The division? Really? In those dark days, it seemed the Yankees' only shots by now would be on a par-3 hole.
"When we were 14 1/2 back, I just never really thought about the division," Pettitte said. "I wanted to make the playoffs. I knew if we continued to play well, maybe that would be something that we could set our sights on."
Pettitte helped keep the dream alive on Wednesday, scattering seven hits and striking out four in a 104-pitch performance, becoming just the 27th left-hander in big league history to reach the 200-victory plateau.
He jogged off the field and tipped his cap to a crowd of 53,847 after recording the second out of the eighth inning. It wouldn't be the last outburst from the stands.
A half-inning later, with the bases loaded full of Orioles, Toronto's score changed from "2" to "6" on the left-field matrix board, prompting a roar. The Yankees noticed.
"You can't help it," Derek Jeter said. "I wouldn't say we're necessarily looking at the scoreboard, but all you've got to do is listen to the fans."
Toiling with the bases loaded for the second straight appearance, Rivera had little time to savor the reaction. In Sunday's outing at Fenway Park, he'd tested the limits before getting David Ortiz to pop harmlessly into Jeter's glove. This time, Rivera reared back and buzzed a 94-mph offering past Moore on the outside corner, securing the Yankees' 12th victory in 14 games.
Bending, but not breaking. The Yankees were the easy pick to bury by June, mired in fourth place in the AL East and playing listless baseball. Their post-All-Star break record of 45-21 has made countless amateur and professional prognosticators look foolish. Perhaps they revel in that.
"We just wanted to have fun and play our game," Rivera said. "Everything else will just take care of itself. It's good, but still we're behind. We have to keep playing hard and make sure we do what we have to do."
"We have 10 games left," Torre added. "We certainly can't let our guard down."
Helping his team on its way to its sixth sweep in its last 13 series, Hideki Matsui started the Yankees' offense with his 25th home run and second in three games, reaching Baltimore left-hander Brian Burres for a solo shot to right in the second inning.
The Yankees would scrape together another run in the fifth, as Doug Mientkiewicz singled, moved up on a hit and fielder's choice, then scored on a wild pitch. That would be all against Burres, who worked 7 1/3 innings of five-hit ball, but it was enough.
More and more, the Yankees' evenings seem to be taking on Octoberesque traits, thick in importance even as the schedule winds down against clubs relegated to the spoiler role.
"I think it's the time of year, there's no question," Torre said. "We spent an early portion of this year trying to find our way. Now, when we come to the ballpark, we expect to win. It's a nice feeling."
Perhaps foreshadowing a pivotal moment of a potential Division Series, the Yankees altered their use of relief phenom Joba Chamberlain in the late innings, warming up the 21-year-old but only using him for one out -- the first time Chamberlain has entered a contest mid-inning in his brief Major League career.
The experiment, which Torre said had been signed off on for about a week, went without a hitch, as Chamberlain gassed Melvin Mora to end the inning. At this point, rules -- even the highly secretive "Joba" ones -- are made to be ... well, bent.
"We've got to play every game like it's a playoff game," Chamberlain said. "Everybody's playing well, and we've put nine innings of baseball together the last couple of weeks. It's good to see everything coming into place."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.