Josh Hamilton had three doubles, drove in a run and scored once, but left the game in the seventh inning with a sore right knee.
Tommy Hunter (6-0) won for the sixth time in his eight starts this season as he was charged with two runs on five hits with two walks and a strikeout over 6 2/3 innings.
J.D. Drew and Bill Hall each homered to account for the offense for the Red Sox, who have lost six of their last eight. Tim Wakefield (3-8) was tagged for seven runs -- six earned -- on eight hits in just two-plus innings of work.
The Rangers jumped on Wakefield in the first inning. With one out and two on, Guerrero singled home one run and Hamilton followed with an RBI double. Cruz then brought in two more with a single and Molina followed by crushing a 1-0 pitch over the Green Monster for a 6-0 lead.
Cruz smacked an RBI double in the third to extend Texas' lead to 7-0.
Boston got on the board in the fourth when Drew smacked a homer over the wall in left.
Hall blasted a pitch over the left field wall in the seventh.
Each team has won twice in the season-series, but Texas has captured eight of the last 11...Colby Lewis takes the mound for Texas on Friday and will be opposed by Felix Doubront for Boston...Wakefield is 10-16 over 35 meetings against Texas.