On May 11, 2005 — The Boston Red Sox end a game for the second consecutive day by hitting a walk-off home run off the same pitcher, a feat only accomplished five previous times in major league history. Oakland Athletics closer Octavio Dotel, who gave up the decisive blast to Kevin Millar the previous day, is victimized today by Jason Varitek in the bottom of the 9th inning, to beat Oakland, 6 – 5.

Source:
Baseball Reference May 11