After Reynolds' solo homer in the fourth inning of Saturday's game at Fenway Park, Reynolds is 16-for-36 (.444) in 11 games against Boston this season with four doubles, six homers, nine runs and 16 RBIs.
He took a 2-0 sinker from Boston starter Aaron Cook over the Green Monster in left field to give the Orioles a brief 3-1 lead.
Reynolds also had two hits and drove in a run in Friday's series opener against the Sox, a 4-2 Orioles win.
He entered Saturday's game hitting /435/.563/.826 with two homers and eight RBIs in seven games this season at Fenway Park
Sixteen of Reynolds' 22 homers and 40 of his 67 RBIs have come against the AL East. He entered the day hitting .287/.397/.614 against division opponents.