"He's the best pitcher I've ever had the chance to catch," Barajas said.
Halladay (11-3) could also be the biggest prize available before the July 31 trade deadline. Blue Jays general manager J.P. Ricciardi said this month he would field offers for the 2003 AL Cy Young Award winner, who is signed through 2010.
"I stand by what I said the other day," Red Sox manager Terry Francona joked. "They should have traded him the other day, and to a National League team."
Pitching at home for the first time since Ricciardi's comments, Halladay turned in a vintage performance. He struck out six and walked none, lowering his ERA to 2.73.
After addressing the trade speculation at last week's All-Star Game, where he started for the American League, Halladay put all the talk behind him as he focused on the second half.
"As much as a circus as that was, it kind of allowed me to get back here and just kind of put it out of mind and get back to my job," Halladay said. "It's hard to do. You do hear those things, but you've got to do the best you can to put it out of mind and focus on what you're doing."
With 36,534 fans on their feet, Halladay tipped his cap to the crowd as he headed back to the dugout following the final out. He insisted it wasn't a wave goodbye.
"You have to kind of live in the moment and that's all I'm trying to do," Halladay said. "It has nothing to do with looking down the road. It's just a matter of the fans were excited, they were cheering and that's all it was."
Halladay retired his final 11 batters and threw 78 of 105 pitches for strikes in his 44th career complete game and fourth this season.
"We're a team that, a lot of the time, works counts and takes pitches," Boston slugger Jason Bay said. "There's a few guys that's not really conducive for and [Halladay] is one of them. You look at his strike-to-ball ratio and it's ridiculous. It's one of those things where you're not going to wait him out and work a walk."
Halladay won for the first time in four starts since beating Kansas City on June 7. The right-hander improved to 1-2 since coming off the disabled list June 28 after missing two turns with a sore groin.
"I felt location was better today," Halladay said. "The first couple of times [off the disabled list] I was just having a hard time getting in that rhythm. From about the fourth inning on I felt I was able to get ahead and work ahead."
Boston's lead in the AL East was trimmed to one game over the New York Yankees.
David Ortiz gave Boston a 1-0 lead with a sacrifice fly in the first inning but Barajas put the Blue Jays in front with a two-out, two-run double in the second off left-hander Jon Lester (8-7), snapping an 0-for-20 slump.
Barajas gave the Blue Jays some insurance with a sacrifice fly in the sixth.
Lester came in 2-0 against Toronto this season and had won five of his past six decisions. But he lost for the first time since June 18, yielded three runs and five hits in seven innings. Pitching for the first time in nine days, he walked a season-high four and struck out six.
"I was sharp at times and not so sharp at other times," Lester said. "I had to shake off a little bit of rust and inconsistency in certain innings and that was the ballgame."
- Jacoby Ellsbury returned to Boston's lineup after missing two games with an illness. Toronto OF Vernon Wells (illness) missed his third consecutive game.
- Red Sox RHP Daisuke Matsuzaka, out since June 21 with a strained shoulder, will be in Boston later this week to see team doctors. Matsuzaka is rehabbing in Florida, where he is throwing up to 120 feet on flat ground.
- Toronto had not won a series since taking two of three from Cincinnati from June 23-25.