The Marlins were keeping a watchful eye on Punto at first. Heaney made a throw over with the left-handed-hitting Stephen Vogt at the plate.
Seeing Punto off the bag, Mathis countered by executing a perfect throw to Jeff Baker at first base for the out.
"It's just something I'm always looking for, an aggressive secondary [lead]," Mathis said. "I'm just glad to get an extra out."
It wasn't just any throw.
From his squatting position, Mathis used Vogt to shield Punto's view. The behind-the-batter throw was perfect, and Baker applied the tag for the undisputed out.
The next play, Vogt grounded to third, ending the inning.
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter