Philadelphia responded in the next half-inning against Fernando Abad (0-2) when Ben Revere led off with a single and went to third one out later on a Jimmy Rollins base hit.
After Abad fanned pinch-hitter Steve Lerud for a second out, Brown came through with a solid hit up the middle for a walk-off game-winner.
Jonathan Papelbon (1-0) got the win despite allowing Tracy's game-tying homer as the Phillies took the first of a three-game series.
Ryan Howard went 3-for-3 with a solo homer and an RBI single for the victors.
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