Dunn denied HR on instant replay
Dunn, who earlier homered in the first inning, appeared to hit his second off San Francisco Giants starter Barry Zito with one out in the seventh. The ball sailed high and bounced off the top of the wall in right-center field.
Dunn rounded first then appeared to slow into a home run trot before stopping at second when first base umpire Casey Moser ruled the ball in play. After Washington manager Jim Riggleman came out to argue the call, Moser met with the other three umpires and the quartet left the field to watch the replay before returning with their ruling.
The Nationals lost, 5-4.
Information from The Associated Press was used in this report.