Via ESPN Chicago:
Pierzynski had just driven in Alexei Ramirez from first base with a double to tie the score against the Orioles at 2-2. He was moving to third on the throw home when he appeared to be pumping his fist in celebration between bases.
Orioles catcher Matt Wieters nearly gunned down Pierzynski at third base. When he didn’t slide, Pierzynski’s left ankle rolled as he tried to step on the bag.
The Sox currently lead the game 3-2 in the top of the ninth.