Fowler lifted a 2-2 fastball from Joel Hanrahan off the top of the wall in left-center field -- in front of the bullpen -- that bounced back into play as he was rounding the bases. Second-base umpire Eric Cooper signaled for a home run before Pirates manager John Russell came out to argue and the crew gathered to review the play.
The review marked the fourth in PNC Park history, three of which have now been overturned.
Matt Fortuna is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.