BALTIMORE -- Oakland's John Jaso was denied a grand slam in the third inning against the Orioles at Camden Yards on Sunday when the umpires overruled the initial home run call and awarded Jaso a two-run double.
With nobody out and the bases loaded following three straight walks by Orioles starting pitcher Ubaldo Jimenez, Jaso belted a line drive toward the top of the wall in right-center field. As Jaso trotted in to second base, second-base umpire Larry Vanover waved his arm to signal home run.
But even before the Jaso crossed home plate, O's manager Buck Showalter was out of the dugout and ready for a discussion.
The crew chief decided to look at the play, so it didn't count as a challenge for Showalter, and the call was overturned.
Instead of a grand slam, Jaso was awarded a two-run double. Two runs came off the board, but Oakland still had a 2-0 lead and runners on second and third with no outs against an increasingly shaky Jimenez.
After Jimenez's fourth walk of the inning, Brandon Moss left no doubt with a grand slam to deep right, giving the A's a 6-0 lead.
David Wilson is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.