Rapid reaction: Red Sox 10, Yankees 4

BOSTON -- So, what is a more vexing problem for a team headed to the postseason: Trying to determine the identity of your No. 3 starter, or figuring out why your ace can’t beat your archrival?

Those are the separate issues faced by the Red Sox and Yankees, and underscored by the proceedings here Saturday afternoon at the Fens.

John Lackey, Boston's incumbent No. 3 with Clay Buchholz on the shelf, pitched without a net again Saturday afternoon, with Yankees clogging the base paths at every turn. But he was at his competitive best in the fifth inning, when he quashed a Bronx uprising by striking out Curtis Granderson and Mark Teixeira and retiring Robinson Cano on a roller to first.

By the time Lackey left, after six innings, the Red Sox were comfortably ahead, 7-3, against CC Sabathia, who is a world-beater against everyone else but is a perplexing 0-4 against the Red Sox, who became the first team ever to beat the All-Star left-hander four times in a single season.

The Sox, pulling back into a first-place tie with the Yankees, scored as many runs Saturday against Sabathia as the Yankee ace had allowed in his previous eight starts combined, treating him like he was Jo-Jo Reyes instead of the majors’ leading winner.

That does not bode well for the Bombers in October, given that his ERA against the Sox is 7.50; against the rest of baseball it's 2.11.

Jacoby Ellsbury, who knocked in a career-high six RBIs, became just the second left-handed hitter this season to take Sabathia deep when he launched a three-run home run that landed in the first couple of rows of the right-field grandstand. That was in the fourth inning, when the Sox scored five times off Sabathia, who gave up a leadoff double to Kevin Youkilis and singles to Mike Aviles, Carl Crawford and Marco Scutaro before Ellsbury took him out of the yard.

Ellsbury also had a sacrifice fly in the third, and a two-run single in the eighth off Yankee reliever Hector Noesi. Ellsbury, on pace to drive in 104 runs out of the leadoff spot, became the first Sox leadoff man to drive in six or more runs in a game since Ellis Burks drove in seven on June 10, 1987.

The other big offensive splash of the afternoon belonged to Carl Crawford, who had four hits, scored three runs and stole a base. Crawford also had hits in his last two at-bat Friday, giving him six hits in six at-bats after having just a total of five in the first nine games played between the teams.