Thomas hit three home runs to lift the Toronto Blue Jays over the Red Sox 6-1 on Monday night, raising his total to 512 and tying Ernie Banks and Eddie Mathews for 18th on the career list.
"It was one of those days everything clicked," Thomas said. "I'm just happy. Really happy."
Boston lost for the third time in four games and its AL East lead was cut to 3½ games over the New York Yankees. That's the smallest division margin for the Red Sox since before play on May 2.
"We've got to grind it out," Tim Wakefield said.
Thomas homered twice off the knuckleballer, then hit his third against reliever Kyle Snyder. Thomas had three homers one other time -- hitting all of them off Wakefield at Fenway Park on Sept. 15, 1996.
"I remember it like it was yesterday," said Wakefield (16-11). "There's a reason he's got 512 homers. If you make mistakes to him, they leave the yard pretty quick."
Thomas said he had extra motivation on that day 11 years ago.
"It was funny because Mo Vaughn is a very good friend of mine and he hit two that day," Thomas said. "We were really going at each other."
Thomas is a career .250 (12-for-50) hitter against Wakefield.
"I've had my good days against him but over the whole haul, he's had the best of me," Thomas said. "Today a couple flattened out. That happens with knuckleball pitchers sometimes."
Dustin McGowan (11-9) pitched a five-hitter, struck out nine and walked none.
"Dustin was tremendous today," Thomas said. "When he's prepared mentally, he's as good as any starter in baseball. I know that's a bold statement, but it is true. His stuff can totally dominate a team. When he's on, he's on. I don't care how good the hitters are."
Thomas hit a two-run homer in the first, then added a solo shot off the left-field foul pole in the sixth to tie Mel Ott on the career list. Thomas connected again in the eighth to raise his total off Boston pitchers to 40, the most among active players.
It was the fourth multihomer game of the season for Thomas and the 33rd of his career. He also homered Saturday off Baltimore left-hander Kurt Birkins.
Wakefield allowed four runs and seven hits in six innings with two walks and two strikeouts. He is 0-1 in three starts since missing a turn on Aug. 31 because of a sore lower back.
"I felt like I had good stuff," Wakefield said. "I'd like to have just two pitches back, and both of them were to Frank."
McGowan pitched his second complete game in 35 major league starts -- he threw a one-hitter against Colorado on June 24, allowing Jeff Baker's leadoff single in the ninth.
"I felt like I had good stuff, everything except a good curveball," McGowan said.
That didn't stop him from holding David Ortiz to an 0-for-4 night, striking the Boston slugger out three times.
"I just enjoy getting him out," McGowan said. "It doesn't matter if it's a strikeout. He's one of the best hitters in the game."
Boston catcher Kevin Cash, a former teammate of McGowan's in Toronto, was left shaking his head after striking out twice.
"You don't like to say the best you've ever seen but his combination of pitches tonight was as good as I've ever faced," Cash said. "When you're throwing 98 miles per hour in the ninth inning, that's pretty impressive."
Already without Manny Ramirez (strained left oblique) and Kevin Youkilis (sore right wrist), Boston manager Terry Francona said Ortiz is battling a sore knee and center fielder Coco Crisp has a stiff back.
"We're going to have to fight through here for a few days," Francona said. "David doesn't feel great."
McGowan retired his first nine batters before a leadoff single in the fourth by Jacoby Ellsbury, whose 13-game hitting streak ended Sunday night. Mike Lowell lined a two-out RBI double that barely eluded left fielder Adam Lind.
McGowan retired his next 12 batters, a stretch that ended with Alex Cora's two-out double in the eighth. He got some help from his defense, most notably by an over-the-shoulder catch by Vernon Wells, who raced back to the warning track in center to snare Eric Hinske's drive opening the eighth.
Wells led off the first with a walk and scored on Thomas' two-out homer, then drove in Toronto's third run with an RBI grounder in the fifth. Matt Stairs followed with a single, but Wells ended the inning by getting thrown out at third base by Crisp.
- The Blue Jays matched a season high with three stolen bases.
- Boston had won its prior five games in Toronto.
- Alex Rios reached in the eighth when Cora slipped and fell on his chest while throwing to first.