The brief meltdown by Halladay led to a four Boston runs, which proved to be plenty for Red Sox right-hander Josh Beckett to cruise to his Major League-leading 17th victory. The loss, coupled with the Yankees' win in New York, pushed Toronto (70-68) 6 1/2 games away from the American League Wild Card lead.
"This puts us in a hole," Toronto first baseman Lyle Overbay said. "We've got to get out of this and move on. Time is running out. We can't really do this anymore if we're going to make the playoffs."
The turning point for Halladay (14-7) and the Jays on Tuesday arrived in the fourth inning, after he and Beckett (17-6) matched zeroes for three frames. Toronto's right-hander issued a leadoff walk to J.D. Drew, who then advanced to third base on a single to right field by Boston first baseman Kevin Youkilis.
With runners on the corners and one out for the Red Sox (84-55), Halladay induced a ground ball off the bat of Coco Crisp. Blue Jays second baseman Aaron Hill gloved the ball and relayed it to shortstop John McDonald, who attempted to turn an inning-ending double play.
Halladay was already walking toward Toronto's dugout when first-base umpire Kerwin Danley threw his arms up in the air, motioning that Crisp was safe. That allowed Drew to score Boston's first run and set Halladay's tailspin in motion.
"It was one of those things where it could've got us out of the inning," Overbay said. "But it ended up being a big call. I'm not going to say [Danley] was right or wrong -- I don't know. It could've gone either way. It was pretty close. I just wish it would've went the other way."
The next pitch that Halladay threw tailed away from Red Sox rookie Jacoby Ellsbury, but the young outfielder managed to get the barrel on the ball. Ellsbury lifted the offering deep to right field, where it came crashing into Boston's bullpen. As Ellsbury rounded the bases, television cameras caught Halladay yelling profanely in Danley's direction.
Halladay then yielded consecutive doubles to Julio Lugo and Dustin Pedroia, putting the Blue Jays behind, 4-0. The pitcher finally forced David Ortiz into an inning-ending grounder, but not before creating a hole too deep for Toronto's hitters to overcome.
"It's just a break that didn't go our way," Halladay said about the call. "Unfortunately, I let it bother me a little bit and I didn't make as good pitches after that. That's probably more important than whether he's out or safe.
"I just didn't do a good job of settling myself down," he continued. "I should've focussed on executing. Sometimes you get caught up in maybe what could've been and it affects your focus and execution. Really, that's what I think happened."
The Blue Jays pieced together a minor rally in the fifth inning, when 39-year-old Matt Stairs maintained his torrid pace at the plate with a three-run homer off Beckett. The comeback was short-lived, as that blast accounted for the only offense during Beckett's eight crisp innings.
In the eighth, Youkilis belted a solo homer to center field off Halladay, padding the lead for Red Sox closer Jonathan Papelbon -- not that he needed any help. Papelbon set Frank Thomas, Troy Glaus and Overbay down in order in the ninth to seal the disheartening defeat for the Jays.
"When Stairsy had the big three-run homer, I thought we were going to bounce back," Toronto manager John Gibbons said. "But Beckett was great tonight. Then, when you get to Papelbon, it gets that much tougher."
The rare lapse in concentration by Halladay made the fact that he turned in his seventh complete game -- the most in baseball -- a moot point. For once, it was a lack of focus that doomed the Blue Jays' leader.
"It's just a matter of making pitches one at a time," Halladay said. "As soon as you lose sight of that, it always seems to come back and bite you."