New York led the AL East by 10 games on July 18, but now stand one game ahead of the Baltimore Orioles for the division lead. New York has gone 37-33 since then, compared to the Orioles' 46-24.
A loss for the Yankees and a win by the Orioles Wednesday would tie them and force a one game playoff.
Both have already sealed playoff berths, but the division winner would avoid a wild card spot and a one-game elimination match with either the Oakland Athletics or the Texas Rangers.
Left fielder Raul Ibanez kept New York's hopes alive Tuesday night with a two-run home run in the bottom of the ninth inning to knot the game at 3-3 and force extra innings.
Later in the 12th, Ibanez slapped a single to shallow left center and catcher Francisco Cervelli scored from second to sew up the 4-3 win.
Like the Yankees, the Red Sox certainly understand dwindling division leads, losing the AL East crown last season despite opening up a nine-game buffer heading into September.
The 2012 season has been just as disappointing for the Sox. Currently at 69-92, Boston will have their first 90-loss season since 1966, when they went 72-90.
Taking the mound Wednesday for the Yankees is Japanese native Hiroki Kuroda, who has a 15-11 record and sports a 3.34 ERA on the season.
In his last outing against Boston, Kuroda went 6.1 innings and gave up four earned in a 4-3 loss for New York on Sept. 11. For the season, Kuroda gave up 12 earned runs against the Red Sox, striking out 17.
Boston will counter with right-hander Daisuke Matsuzaka, who hasn’t faced the Yankees since 2010, and is 0-3 with a 13.50 ERA in his last four starts. Opponents are also hitting .400 against him.
Prediction: New York is certainly motivated and would like to avoid a one-game elimination match-up, while Boston is equally pumped to thwart the rival Yankees. But New York are 9-1 in their last 10 home games, and have won four straight against the Sox for a 12-5 season series advantage. New York should prevail in the closing innings.
Predicted Score: Yankees 6, Boston 4