McCann hit two homers, including a three-run shot in Atlanta's seven-run seventh inning, and the Braves beat the Blue Jays 10-2 on Sunday to cap a three-game sweep.
The Blue Jays were the first team that tried to stop McCann by placing three players on the right side of the infield.
It may be a long time before McCann faces another shift.
McCann had three hits and drove in four runs, leaving him 6-for-10 in the series. He is hitting .396 (19-for-48) in 14 games with his new glasses.
"We can't be satisfied with the sweep," McCann said. "We've got to keep going."
McCann missed 13 games while on the disabled list from April 23 to May 8 with blurred vision, including a failed experiment with contact lenses.
The score was 2-all before pinch-hitter Chipper Jones drove in the go-ahead run with a bases-loaded single in the seventh.
Jones missed the first two games of the series after hurting his right big toe on Thursday night. He didn't start on Sunday but made good on his first pinch-hit appearance of the season.
"I'm glad that the opportunity arose," Jones said. "When you're sitting there you're just hoping to get an opportunity to have an influence on the game."
The sweep was the Braves' first in eight series with Toronto.
The Blue Jays' six-game losing streak is their longest since dropping seven straight last June. They fell to second place in the AL East, a half-game behind Boston.
"We're OK," said Toronto manager Cito Gaston. "We're still ... just a half-game out."
Toronto, which began its nine-game road trip with three straight losses at Boston, has been swept in back-to-back road series for the first time since May 2007 at Cleveland and Texas.
"You're going to go through periods like this," Vernon Wells said. "Hopefully, we'll right the ship and get back at it tomorrow."
Wells had two hits and scored both Toronto runs but said "I take a lot of responsibility" for the losing streak.
"It's frustrating for everyone," he said.
Kelly Johnson had three hits, including a homer, and drove in three runs for Atlanta, which completed a 6-3 homestand.
The Braves had 13 hits, including five in the seventh, when they sent 10 batters to the plate.
"It looks like everybody's finally in a groove," McCann said. "Everything fell into place."
Jeff Bennett (2-1), Atlanta's third of five relievers, recorded one out in the seventh.
Shawn Camp (0-2) gave up the first three runs in the seventh. Left-handed batters were 1-for-22 against Toronto right-hander Jason Frasor this season before he gave up three hits to lefties in the seventh, driving in six runs.
Jones greeted Frasor with an RBI single off first baseman Lyle Overbay's glove for a 3-2 lead. Johnson followed with a two-run double, Garret Anderson had a sacrifice fly and McCann added a three-run homer off Frasor into the Braves bullpen to cap the seven-run inning.
"Everybody did get in on it, but the biggest hit of the day was Chipper's," said Braves manager Bobby Cox. "I asked him in the fifth inning if he could go. He said, 'I can hit, I don't know if I can run or not."'
Cox said he was going to use pitcher Kris Medlen as a pinch-runner. Jones, thinking Cox was going to weaken the bench by using a position player, waved off the pinch-runner.
The seven runs were the most allowed by Toronto in an inning this season.
Johnson and McCann hit first-inning home runs off Scott Richmond.
The Blue Jays pulled even with runs in the fourth and sixth innings off Jair Jurrjens, who gave up eight hits and two runs in six innings.
Wells singled, stole second and third, and scored on Jose Bautista's groundout. Wells led off the fifth with a double and scored on Overbay's one-out single, making it 2-all.
- Braves SS Yunel Escobar (right hip flexor) did not play. Diory Hernandez, playing in place of Escobar, singled in the seventh for his first major league hit and added another single in the eighth.
- Wells matched his career high with the two steals.
- Johnson's homer was his second in two games and his fifth career leadoff homer.