He ended the game with his third hit of the night, a high-hopping infield single with two out and the bases loaded in the bottom of the 12th inning that gave his club a 6-5 victory in the second game of a three-game series.
"I'm pretty sure it hit the plate," said Buck, who barely beat Boston second baseman Dustin Pedroia's throw to first. "Pedroia made a great play to make it close, but I'm pretty sure I got there before the ball. I had to make it."
Had he not, the two teams might still be playing. Or they'd be frozen in place at Oakland-Alameda County Coliseum.
When lefty Dana Eveland delivered the first pitch, the game-time temperature was announced at 50 degrees. Four hours and 24 wind-whipped minutes later, when pinch-runner Rajai Davis scored the winning run, it felt like 50-below to some of the survivors.
"It was a tough game," A's manager Bob Geren said. "It was windy, it was cold. I don't know if it's ever been this cold here before."
It hasn't since Buck made his A's debut in 2007.
"Wow," he said when asked about the conditions. "I mean, it was freezing."
Early on, however, the bats for both teams were hot. Boston bolted in front with three runs on four hits and two walks in the top of the first inning, only to be topped by Oakland's five-spot in the bottom half.
The A's got a two-run double from Matt Holliday and RBI singles from Jack Cust, Buck and Mark Ellis in the first, sending righty Daisuke Matsuzaka to an early exit with arm fatigue.
"That was a real boost," Geren said. "To come back and get those runs after going down three runs right off the bat, and to get them off a pitcher like Matsuzaka, that's huge."
Eveland, who threw 108 pitches before being pulled with the score tied and two out in the fifth, was charged with five runs on eight hits and three walks.
Righty relievers Andrew Bailey, Santiago Casilla, Russ Springer and Brad Ziegler combined on 6 1/3 innings of four-hit work after Eveland's departure, and Sean Gallagher got the win with a perfect frame.
"Our bullpen was incredible," Eveland said. "I obviously wasn't."
The bottom of the 12th was fairly incredible, too.
Red Sox lefty Javier Lopez walked Jason Giambi to start it, and typically that's where Geren would call on Davis to run for the big fella. But with third baseman Eric Chavez unavailable and his backup, Nomar Garciaparra, on the bench with tightness in his right calf, Geren wasn't comfortable using Davis at that point.
Only Davis and backup catcher Landon Powell, a lumbering sort, had not yet played. Even after Holliday grounded out, pushing Giambi to second, Geren stood pat.
"I knew I could use Landon at first base if I absolutely had to," the skipper said. "But you can't really count on a hit there."
After consecutive walks to Cust and Bobby Crosby, Davis finally got the call.
"Just for the sacrifice-fly factor," Geren explained.
The sacrifice fly never came. Kurt Suzuki struck out, leaving everything in Buck's ready hands -- and mind.
"I had all the trust in the world that 'Zook' was going to get it done," Buck said. "But just in case he didn't, I knew I had to be mentally prepared to have his back. ... And I knew I had to find a way to get the ball in play."
When he did, Pedroia had to wait, helplessly, for it to come down before trying to make the lightning-quick transfer from glove to hand before firing.
"I threw it as fast as I could, got rid of it as fast as I could," Pedroia said. "He just runs well. It didn't really help that he's left-handed, too."
Still, Pedroia said he thought he got Buck -- until peeking at a replay.
"He beat it out," said the reigning American League MVP. "I thought he looked out at the time. Then I checked it on tape; it looked like he beat it."
Mychael Urban is a national writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.