Blue Jays first baseman Lyle Overbay rounds the bases as Oakland Athletics first baseman Jason Giambi walks off the field. Overbay hit a two-run homerun to defeat the A's 4-2 in 12 innings, Saturday afternoon at the Rogers Centre. (Nathan Denette/Canadian Press)

Lyle Overbay hit a walk-off, two-run homer in the bottom of the 12th inning to lead the Toronto Blue Jays to a 4-2 win over the Oakland Athletics on Saturday at the Rogers Centre.

The win gives the Blue Jays (9-4) their best start since 2001.

Neither team had scored since the sixth inning, as both bullpens were in control, but Toronto finally broke through against Dan Giese (0-1).

After Giese retired the first two men, Jose Bautista drew a walk, then Overbay drilled a fastball into the right-centre-field seats.

"I was just looking for something up in the zone that I could drive," Overbay said. "[Giese's] a guy who has to throw everything and it was just a matter of getting a good pitch to hit."

Jason Frasor (2-0) picked up the win after pitching two-thirds of an inning.

Making his first start in nearly three years, Brian Tallet (0-0) more than held his own. The southpaw, making a spot start for injured righty Jesse Litsch, went 5 1/3 innings, holding the Athletics to two runs (one earned) on four hits, a walk and a strikeout.

"He gave us some room there to not use our bullpen so early even though we did use it all," Blue Jays manager Cito Gaston said. "But without him it would have been worse. The bullpen did a really good job, they really did."

A's rookie starter Trevor Cahill (0-1) had some control issues, but managed to keep the Jays at bay, holding them to two runs over 5 1/3 innings despite five walks.

Tallet gets early scare

Just two pitches into the game, the Blue Jays received a bit of a scare when Ryan Sweeney hit a scorching line drive that appeared to glance off Tallet's pitching hand.

The pitcher recovered to make the throw, but put a wild toss down the right field line that allowed Sweeney to reach third.

"When I went to pick that ball up I had no feeling in my hand," Tallett said.

After a visit by trainer George Poulis and Gaston, Tallett took a few warm-up pitches and continued.

"Until after that first warm-up pitch it was still a little numb," Tallett said. "When (the first warm-up pitch) came up a little high they said, 'Hey, don't try to be a hero.'

"The next couple of pitches I got a decent feel of the ball and threw a little breaking ball in there to see if it would affect that and it didn't. So I told them I'm good."

Two batters later, Jason Giambi brought home the game's first run with a groundout.

Capitalizing on some wildness by Cahill in the fourth, the Jays knotted the score at 1-1. After three walks loaded the bases, Travis Snider beat out a potential double-play grounder to plate Adam Lind.

The Jays were denied the chance for more runs on a great defensive play by Orlando Cabrera. After the bases were reloaded, Aaron Hill hit a sharp grounder toward the hole, but Cabrera slid to his right, popped up and fired a throw across to get Hill by half a step.

Scutaro comes through

Shawn Camp came in for Tallet with Giambi at third and one out in the sixth, and was able to strand the runner thanks to a strong defensive play by shortstop Marco Scutaro.

Holliday hit a soft liner that Scutaro dove to his right to snare. Camp then struck out Jack Cust to end the threat.

The Jays tied it again in the bottom half of the sixth, as Lyle Overbay hit a leadoff double, moved up on a sacrifice bunt by Rod Barajas and came in on a single by Snider.

Toronto sends Ricky Romero (1-0, 2.57 ERA) to the mound Sunday in the rubber game as Oakland counters with Dallas Braden (1-1, 3.75).