Overbay homered twice and had five RBI in the first two innings and the Blue Jays won their season-high fourth straight game, an 8-1 victory over the Philadelphia Phillies on Friday night.
Boston won 12 straight before losing at Florida on Friday night, allowing the Toronto to move within four games of first place in the AL East.
"It will happen. The Red Sox are doing it. It's just a matter of finding our groove," Overbay said.
Overbay hit a three-run homer off Adam Bernero (0-1) in a four-run first inning, and added a two-run shot off Bernero in a four-run second.
Eric Hinske also homered for the Blue Jays, who have won seven of nine to move to 11 games above .500 (45-34).
Hinske went 2-for-4 in his first professional start in the leadoff spot. He placed Alex Rios, who remained in the hospital on Friday because of a serious infection in his left leg.
"It just a matter of getting a chance," said Hinske, who lost his platoon job when Rios got off to a hot start.
Staked to an 8-0 lead in the second, Casey Janssen (6-6) pitched six scoreless innings, allowing five hits, while striking out three and walking three.
"It was good to bounce back. The team has been on a roll. I just wanted to keep it going," said Janssen, who won for the first time in four starts.
David Dellucci homered in his third straight game for the Phillies, who have lost eight of nine and 16 of 20.
"It's tough. Things haven't gone the way we wanted them to," catcher Sal Fasano said.
Bernero walked the first two batters he faced, Hinske and Frank Catalanotto, before Troy Glaus hit a one-out, grounds-rule double. Overbay followed with a homer to right, giving Toronto a 4-0 lead.
Hinske led off the second with a homer and Glaus hit an RBI double before Overbay made it 8-0 with his 14th homer. It was his second multihomer game this season and fourth of his career.
Bernero allowed eight runs and seven hits in two innings in his first start in the majors since July, 2004.
"It's not the good first impression you want to make with your new teammates," Bernero said.
He was forced to borrow teammate Ryan Madson's glove and spikes because his luggage was lost.
Dellucci led off the seventh with a homer off Jason Frasor -- the second time he's homered in three straight games. He did it last June 30-July 2.
Fabio Castro pitched three scoreless innings in his debut for the Phillies, who acquired him from Texas on Thursday.
Rios could be sidelined through the All-Star break. He fouled a ball off his leg during Tuesday's 6-0 victory over Washington and the area swelled. He sat out Wednesday's game as a precaution but the pain got worse Thursday, causing the team to send him to the hospital. ... Philadelphia RHP Jon Lieber will make his third rehab start on Saturday for Class-A Clearwater. Lieber has missed the last month with a strained left groin.