Sheffield broke a 1-1 tie when he hit the first pitch from the Nationals' John Lannan to left field, where a fan attempting for the catch made contact with the ball. Although the ball fell back onto the field, third-base umpire Adrian Johnson immediately signaled for a home run. The ruling was confirmed after a six-minute review.
"I'm a fan of getting it right," manager Jerry Manuel said after the game. "If they got it right, that's what's important."
The Mets have benefited greatly from video replay the past three games, beginning in Boston on Saturday, when Omir Santos' game-winning two-run homer in the top of the ninth inning was originally ruled a double. That call was overturned upon review, giving the Mets the 3-2 victory.
In Sunday's finale at Fenway Park, a Kevin Youkilis shot to left was confirmed as a foul ball by a replay review. Youkilis later hit a three-run homer in Boston's 12-5 win.
Tim Britton is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.