Halladay, at the center of trade rumors for the past couple of weeks, turned in a premium performance, firing a complete-game victory in the rubber match of a three-game series.
And speaking of the trade rumors, Sox manager Terry Francona kiddingly wonders what Blue Jays general manager J.P. Ricciardi is waiting for.
"I kind of stand by the statement I made the other day. They should have traded him the other day, and to a National League team," Francona said. "You don't tip your hat during a game because you want to beat him, but that was a pretty good pitcher."
Lester wasn't too shabby, either, giving up five hits and three runs over seven innings while walking four and striking out six.
"I still have to do my job, and I can't control what he does," said Lester. "It's one of those deals where I just tried to pitch my game as best I could, and I think the walks -- if I don't walk those guys, it's a different ballgame."
But it also would've been a different ballgame if Jason Bay had belted his 21st homer of the season in the first inning instead of watching center fielder Alex Rios snag it at the wall for a long out.
If Bay's shot had just a little more carry, Lester would have had a 3-0 lead before Halladay even threw a pitch. Instead, Boston had just the one run on David Ortiz's sacrifice fly earlier in the inning, a screaming liner that was just deep enough to get Dustin Pedroia home.
"I hit it fairly well, but you're not going to get any cheapies out that way," said Bay. "I thought maybe I got enough of it, but in the end, it would have made a big difference, especially with [Halladay] throwing. In the end, it was just a flyout to center field, and we didn't get anything going after that."
That's because Halladay wouldn't let them. The Red Sox had just one baserunner over the final six innings, on a single by Ortiz. Halladay turned in a complete clinic, walking none and striking out seven while throwing 78 of his 105 pitches for strikes.
With the loss, the Red Sox now lead the Yankees by just one game in the American League East.
"We're a team that works counts and takes pitches, and there are a few guys that's not really conducive for, and he's one of them," said Bay. "You look at his strike-to-ball ratio and it's ridiculous. Before the game, I saw he had 100-something punchouts and 17 walks. You're not going to wait him out and work a walk. He gets you to swing at quality strikes he throws. A hundred pitches in nine innings -- he was very efficient and very typical."
For Halladay, it was just another day in the life of one of the best pitchers in baseball.
"Really, it was just getting ahead," said Halladay. "Especially against good teams, you have to be better about not causing problems for yourself. They were aggressive from early on, but you make good pitches early in the count and try to stay out of the middle. If you do it aggressively, sometimes it can help you a little bit and get some of those quicker outs when you need them."
The game-changer, as it turned out, was the bottom of the second, when Lester ran into a hiccup. He walked Lyle Overbay and Rios with one out, both on borderline pitches. Though Lester did settle down to get Kevin Millar on a foul popup, Rod Barajas came through with a clutch two-run double to left to put Toronto on top for good.
"It's one of those deals where [the calls] could go either way, and it went their way," said Lester. "It happens sometimes. I've got to do a better job of stepping back and taking a deep breath and realizing what I need to do and letting it go, and I didn't do that. Like I said, it's one of those days -- just inconsistent, both mechanically and mentally at times."
It could have been the rust coming off the All-Star break, as this was Lester's first start since July 10.
"I think that was probably a little bit of a byproduct of nine days off," Francona said. "I think that we know there's a chance that can happen coming out of the break. I think we also believe in it, and in the long run, it will be good for all of them. That's a long time off. I think it's in all our pitchers' best interest. You don't see him walk guys like that."
The Jays worked Lester hard all day and finally got another reward for their persistence in the sixth when a sacrifice fly to center by Barajas made it 3-1.
In some ways, it was a testament to Lester that he kept his team right there on a day he wasn't at his best.
"He's one of the best pitchers in the league. I know he had a slow start this year, but he's one of the best pitchers in the league," Francona said of Lester. "He knows it -- he should know it. We know it. He pretty much went toe-to-toe with Halladay. He didn't quite match him, but on a lot of days, we're in here saying he walked a couple, but he still pitched great. But it was Halladay."
And on this day, Halladay was just too much.
"He's got great stuff, and the deeper in the game he gets, the better he gets," said Pedroia. "That's why he's the best."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.