The Jackson Generals scored the go-ahead run on an eighth-inning Biscuits fielding error in Friday's 2-1 victory.
Third baseman Robi Estrada mishandled a Ramon Morla two-out groundball, allowing Leon Landry to score and give Montgomery its sixth straight loss.
The Biscuits, who last lost six in a row in May 2011, wasted a combined two-hitter by Enny Romero and Braulio Lara.
Romero gave up one run on just one hit over six innings, though he tied a season high with five walks. Romero did strike out a season-high nine.
Lara (2-2) also allowed just one hit with an unearned run. He walked two and struck out two. Lara hadn't had a run charged to him since July 13, a span of 10 appearances and 16 innings.
The Biscuits scored in the first inning when Mikie Mahtook singled home Shawn O'Malley. O'Malley hit a one-out single and stole second before Mahtook's hit.
Friday marked the second time in franchise history the Biscuits threw a two-hitter and lost -- and both were in games started by Romero. Jacksonville had just two hits in a 1-0 win over Montgomery in the second game of a doubleheader July 26.