Cody Childs started the extra frame with a base hit, and advanced to second on a wild pitch. Chew hit a ground ball through the right side of the infield scoring Childs to give Missouri Western (30-18) a walk-off win the the deciding game of the MIAA Tournament's first round series.
The Griffons advance to the conference tournament's round of four starting Thursday in Springfield. Western will play Northeastern State.
Childs had a career-day at the plate going 4-5 with a home run, RBI and three runs scored. Chew also drove in a pair and scored a run.
Four pitchers pieced together ten innings for the Griffons.
Mark Spreckels allowed three runs -- two earned -- in two innings of work. Tyler Sanders, Josh Lansangan and Mason Queen combine to give up just one run on ten hits with seven strikeouts in eight innings.
Queen won for the fourth time this season pitching the final three innings.