On May 15, 2011 — The Red Sox beat the Yankees, 7 – 5, at New Yankee Stadium, to complete a three-game sweep and bring their record to .500 for the first time after starting the year 0-6. Kevin Youkilis, David Ortiz and Jarrod Saltalamacchia homer for the Sox. The Yankees have now lost 9 of their last 12 as the standings in the AL East are completely bunched up, with all five teams within 3 1/2 games of each other.
Source:
Baseball Reference May 15