But before the three-game set at Fenway Park starts Friday night, Boston has two more games in their season series with Cleveland to finish up and New York has two more with the Chicago White Sox.
At most, they'll enter Friday night's series opener three games apart - if Boston wins and New York loses their next two - so it's easy to say that first place will be on the line this coming weekend.
The Red Sox, who've dominated the Yankees thus far in 2011, going 8-1 against the Bronx Bombers, including winning six straight in New York, hope it won't be a series that sees them vanquish their lead. They've got their pitching lined up - Jon Lester will be followed by John Lackey and Josh Beckett - with eyes on extending their lead.
The current American League East standings:
Boston Red Sox (67-41)
New York Yankees (66-42, one game back)
Tampa Bay Rays (56-52, 11 games back)
Toronto Blue Jays (56-53, 12 games back)
Batlmore Orioles (43-63, 22 games back)
For the latest MLB standings, including a look at the wild-card picture, check out MLB.com's standings page.