Buck doubled home two runs in the 12th inning and the Athletics completed a three-game sweep of the Toronto Blue Jays with a 3-2 win Thursday night.
Buck went 3-for-6 with three RBIs, matching an Oakland record with three doubles.
"We're very confident right now," Buck said. "The Blue Jays aren't going to get swept too many times this year, let alone here."
After starting the season in an 0-for-22 slump, Buck doubled in the second inning Tuesday and ended up going 7-for-16 with four RBIs and six doubles in the series, boosting his average to .189. The six doubles in a three-game series are an Oakland record.
"I just got that first hit out of the way two games ago and started going back to being myself," Buck said. "No matter how good you are, when you're in a slump like that you start to think about it a little bit. You've just got to keep on doing what you did you get to this level, don't change a thing."
The Athletics have won four of six overall, and seven straight in Toronto in a streak that began during the 2007 season.
"The way these three games went and the way we battled all the way to the end and came out on top, everybody did their job this series," Buck said. "We're very proud and we've got to continue it."
Chris Denorfia led off the A's 12th with a single, Bobby Crosby grounded out and Jack Hannahan was intentionally walked before Brandon League (0-1) loaded the bases by hitting Kurt Suzuki. Denorfia was forced out at home on Emil Brown's infield grounder before Buck doubled to left-center.
"He (League) wasn't throwing the split-finger for strikes," Buck said. "We were just going up there looking for the fastball."
Devine almost missed the start of the game after his connecting flight to Toronto was delayed by a snowstorm in Denver. He finally arrived at Rogers Centre about 20 minutes before the first pitch.
"I got here in one piece and was able to be a part of an unbelievable baseball game," Devine said. "It's just one of those things where you've got to get what you did previously in the day out of your head and mentally block it off."
Devine's effort made an impact on his new teammates.
"He did an outstanding job," Buck said. "I don't think too many guys could have done that."
Hannahan made the defensive play of the game with one out and runners at second and third in the ninth. With the infield in, third baseman Hannahan dived to his left to snare a hard grounder off the bat of Marco Scutaro, looked the runners back and got the out at first.
"The play Jack Hannahan made really saved the game," Oakland manager Bob Geren said. "It looked like a hit and he just took it away."
Shortstop Bobby Crosby called Hannahan's play "incredible."
"It was real impressive," Crosby said. "If he doesn't make that play, we lose."
The Blue Jays, who swept a three-game series from Boston last weekend, head to Texas for three this weekend.
"We're going to see what we're made of," Jays outfielder Vernon Wells said. "We haven't played well there for as long as I've been here. If we don't start playing better baseball, the same thing is going to happen to us there."
Oakland opened the scoring in the fifth when Ryan Sweeney singled with two outs and came around on Buck's double to right-center. Toronto tied it in the eighth against reliever Alan Embree. Scutaro led off with a triple and scored one out later on Shannon Stewart's sacrifice fly.
Athletics left-hander Dana Eveland scattered three hits over 6 1/3 shutout innings, lowering his ERA to 0.68. He walked three and struck out six. Blue Jays right-hander Shaun Marcum allowed one run on six hits in seven innings, walking one and striking out eight.
Harden (strained back muscle) was placed on the 15-day disabled list, retroactive to April 3, and will miss his scheduled start at Cleveland on Saturday. Left-hander Lenny DiNardo is expected to start in his place. ... Toronto DH Frank Thomas went 0-for-4 with four strikeouts and two walks. ... Toronto Raptors rookie Jamario Moon threw out the first pitch. ... The Athletics' team record for doubles in a game is four by Frankie Hayes of the Philadelphia A's in 1936.