Loaiza pitched a four-hitter for his first shutout in more than two years, and Frank Thomas and Milton Bradley homered to lead the Athletics to a 6-0 victory over the Toronto Blue Jays on Wednesday night.
Loaiza -- signed to a three-year, $21 million contract in the offseason -- was booed at home in April when he went 0-3 with a 8.35 ERA. He was also arrested for DUI and spent May on the DL.
"Right now, I'm playing good ball and feeling great," Loaiza said. "Whatever was said in April and May was said. I don't read the newspapers."
Loaiza (7-7) retired 15 straight batters during one stretch. He struck out seven and walked none for his sixth career shutout and his first since April 18, 2004, versus Tampa Bay.
Oakland, which began the day with four-game lead over Los Angeles in the AL West, has won 19 of its last 24 games.
Loaiza has allowed just one earned run in his last three starts.
"His last three starts have been terrific. It's a great time for him to be pitching like that," Oakland manager Ken Macha said.
Macha said the difference now is that he's added 10 mph to his fastball because he's healthy.
"From April till now there's probably a whole different view from the fans," Macha said.
Thomas hit his 475th homer, tying Willie Stargell and Stan Musial for 23rd on the all-time list. Thomas hit a two-run shot in the first off Gustavo Chacin (6-3) for his 27th homer.
Bradley's two-run shot in the second made it 5-0.
"I just missed my spots and got hurt," Chacin said.
The left-hander, activated from the disabled list before the game, struggled in his first start after missing more than two months with a sore elbow. He allowed five runs on six hits in just 1 1/3 innings, after going 0-3 with a 9.00 ERA in four rehab starts in the minors.
"He felt good," Toronto manager John Gibbons said. "It was good to see him out on the mound. He's a big part of our team, it just wasn't his night."
Oakland sent 10 men to the plate in the first and scored three runs on Bradley's RBI double and Thomas' homer.
Chacin walked Mark Ellis before Bradley's homer in the second. Jason Kendall's RBI grounder in the sixth made it 6-0.
- Thomas has 1,540 RBI, tying him with Stargell for 37th on the all-time list.
- Loaiza has allowed just one home run in his last seven games after giving up 12 in his first 12 appearances.