The Red Sox gave Buchholz a six-run lead through 2 ½ innings and Boston put together a 13-hit attack in defeating the Yankees for the second time in as many tries.
Temperatures were barely above the freezing mark with a cold wind blowing, but Buchholz allowed just six hits and struck out four while throwing 94 pitches.
Boston produced single runs in each of the first two innings and then came through with a four-run third that was highlighted by a two-run single from Jacoby Ellsbury.
New York lost starting pitcher Hiroki Kuroda to an injured right hand with one out in the second. He was hit on the hand by a line drive off the bat of Shane Victorino, who singled in one of Boston's third-inning runs.
Three of the Yankees' runs came on a homer from Vernon Wells in the eighth.