Will Middlebrooks entered the game in the ninth inning as a pinch-runner for Xander Bogaerts. David Ross tapped a sac bunt to third baseman Miguel Cabrera, leaving third base uncovered. Catcher Brayan Pena made a late break to cover the corner, and Middlebrooks, noticing this, continued to run after touching second base.
Pena did beat Middlebrooks to the bag, but he tagged out the wrong guy.
The throw Pena received spun him around. And while Pena did manage to tag out third-base umpire Rob Drake, he failed to tag Middlebrooks, too.