Reynolds, who was released earlier this week by the Cleveland Indians, was picked up by the Yankees as part of their search for another right-handed power hitter.
Reynolds, batting eighth, blasted the ball out of Fenway Park in Boston with one out and Vernon Wells on base in the second inning. The first baseman also drove in Alex Rodriguez with a single in the ninth inning to become the first player with at least two hits and three runs batted in in his first game with the Yankees since Todd Zeile in 2003.
Reynolds, 30, became the first player to hit a home run in his first at-bat with the Yankees since Andruw Jones in 2011, according to the Elias Sports Bureau. The last batter to hit a home run with men on base in his first at-bat with the Yankees was Cody Ransom in 2008.
Alfonso Soriano continued his hot hitting with a run-scoring infield single in the first inning and a three-run homer in the third. He has driven in 18 runs in the past four games. Soriano became the fourth player with at least three hits and an RBI in four straight games in Yankees history. The last to do it was Johnny Damon in 2006.
Robinson Cano’s single in the fourth gave the Yankees a 7-0 lead. Ichiro Suzuki and Chris Stewart each drove in a run in the ninth inning.
Jonny Gomes, David Ortiz and Jarrod Saltalamacchia each had run-scoring singles for the Red Sox.
Andy Pettitte (8-9) struck out five while allowing three unearned runs on six hits in 6 2/3 innings. Loser Felix Doubront (8-6) gave up seven runs on eight hits in four innings.
The Yankees (63-58) are fourth in the American League East, 7 1/2 games behind the division-leading Red Sox (72-52).
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