Gennett was easily safe at the plate while Gomez tried to take second on the throw to the plate.
Catcher Tuffy Gosewisch fired the ball to Aaron Hill at second and Gomez was initially ruled safe by second base umpire Ted Barrett.
Gibson challenged the call and, after a review of 28 seconds, the call was overturned. While Gomez was the final out of the inning, Gennett had crossed home plate prior to the tag on Gomez, so his run counted.
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.