The Biscuits celebrated their first playoff berth since 2007 after Saturday's 11-4 win over the Huntsville Stars.
Combined with Jacksonville's 3-2, weather-shortened loss at Jackson, Montgomery clinched the Southern League's second-half South Division championship. The Biscuits will begin a best-of-5 semifinal series at Mobile on Thursday.
Matt Buschmann continued his late-season surge, posting his fifth straight quality start and his third straight game with at least seven innings. He gave up two runs on six hits.
Mike Sheridan hit a three-run home run to start Montgomery's scoring in the second inning and reached base five times. He singled and scored in the Biscuits' six-run fifth inning.
Kyeong Kang hit a two-run homer and Derek Dietrich a three-run blast to highlight the six-run outburst. Omar Luna reached base four times and scored three runs.