Houston earned the 8-7 win Sunday at Globe Life Park in Arlington, Texas. World Series MVP George Springer scored the winning run.
Astros designated hitter Evan Gattis was at the plate in the top of the ninth inning during the exchange. Rangers reliever Keone Kela began the inning by walking Springer. He then struck out Alex Bregman, before issuing a free pass to Jose Altuve.
Yuli Gurriel hit a fly ball to center field for the Astros' second out of the inning, before Gattis stepped into the box.
The Rangers righty was up 1-2 in the count against Gattis before throwing a ball in the dirt. Astros manager A.J. Hinch quickly emerged from the dugout to talk to the umpire about the pitch.
The umpires conferred that Kela balked on the play, meaning Springer could come in for the go-ahead run. Kela was called out for the illegal move because he did not set before tossing in the offering. Rangers manager Jeff Banister argued the call to no avail.
Gattis ended the inning by striking out. Hector Rondon struck out the Rangers in order in the bottom of the frame, claiming his third save of the season.
The Astros (42-25) swept the Rangers (27-41) in the four-game series.