Thomas, released by the Blue Jays last month before he rejoined the A's, left in the fifth inning with a slight strain of his right quadriceps muscle where it connects to the knee. He was scheduled for an MRI exam Wednesday.

"I hope it's not serious because I feel like I was the old me in the box. I was feeling good," said Thomas, whose knee has been bothering him since he slid into home plate in Cleveland on May 13 trying to score from second. "I hope it's just a strain."

Smith (3-4) effectively threw all of his pitches to outduel A.J. Burnett (5-5) and the A's carried some momentum from a weekend sweep of the World Series champion Boston Red Sox to their fifth straight win - matching a season best.

Smith had been 0-4 in five starts since beating the Minnesota Twins on April 24. The left-hander pitched 6 2-3 scoreless innings, allowed six hits, struck out three and walked one.

"It kind of does feel good to get a win. It puts a smile on your face and you can carry that into your next start," he said. "I can only control what I can control."

Smith had received one run of support in his last two outings and none in each of his previous three.

"Tell him to take a number and get in line," outfielder Emil Brown said. "There are a lot of guys who have pitched good and we haven't scored runs. I would love for us to score seven or eight runs a game."

Alan Embree allowed Kevin Mench's RBI single in the eighth, and Huston Street pitched the ninth for his 12th save in 14 chances. Toronto saw its five-game winning streak end as the Blue Jays began a nine-game road trip on the heels of a four-game sweep of Kansas City at home.

Mench had two hits after coming in 3-for-22 in his first nine games with Toronto since the Blue Jays acquired him in a trade with Texas on May 9.

"Nobody had many chances. They just outplayed us," Toronto manager John Gibbons said.

Oakland has won all four meetings in the series so far this season, including a sweep in Toronto from April 8-10.

Burnett matched his season high with 10 strikeouts and walked two in 5 2-3 innings, but had his two-start winning streak snapped. Burnett allowed three runs - two earned - on seven hits.

The A's took a 1-0 lead in the second when Brown singled, stole second and catcher Rod Barajas made a throwing error that bounced off Brown's right shin and allowed him to score. Hannahan doubled in the fourth after No. 9 hitter Kurt Suzuki drew a two-out walk and Crosby followed with his RBI single.

"I had the one bad inning - the double and single, both missed spots," Burnett said. "Otherwise, I hit my spots and put them away. ... Three runs or less, even earned or not, I think I'm better than that."

Thomas faced his former team for the first time since being released by the Blue Jays on April 20, but Toronto is still on the hook for all but the prorated share of the $390,000 league minimum portion of his $8 million salary for 2008.

Thomas' bobblehead day was supposed to be Sunday in Toronto, but the Blue Jays put those 10,000 dolls in storage and held a tote bag giveaway instead.

This game also marked the Bay Area return of Marco Scutaro, Oakland's former supersub with a knack for game-winning hits - along with Blue Jays reliever Armando Benitez, who pitched across the bay for the San Francisco Giants. Blue Jays leadoff man Shannon Stewart also spent last season with Oakland.

David Eckstein had a pair of singles after coming off the disabled list and returning to his spot at shortstop. He went on the DL on May 8 retroactive to a day earlier with a strained right hip flexor, which he tested in five rehab games before being cleared to be activated.

Notes

Burnett struck out 10 or more for the 18th time in his career. ... Another former A's player, Matt Stairs, flied out as a pinch hitter in the ninth. ... Oakland 1B Daric Barton returned to the starting lineup after recovering from tonsillitis that kept him out of the Red Sox series save for a pinch-hit appearance. ... Barajas went 0-for-4 with two strikeouts as his 10-game hitting streak was snapped. ... Crosby stole his third and fourth bases of the year, and Brown his third.