Stacy became the school's all-time rushing leader before a sold-out crowd in Nashville. The victory helped solidify Vanderbilt's hopes of making a bowl game for the second straight year.
The Commodores (3-4, 2-3 SEC) overcame a fourth-quarter fumble by Stacy. Clint Moseley overshot an open Sammie Coates on fourth-and-13 with 52 seconds left as Auburn (1-6, 0-5) dropped its fourth straight.
Stacy, a senior who also owns Vanderbilt's single-season rushing record, carried the ball 27 times. He now has 2,670 career rushing yards. His 27-yard run in the fourth quarter broke Frank Mordica's previous mark of 2,632 yards from 1976-79.
Auburn, just two years after winning the national championship, is off to its worst start since losing six of its first seven in 1952 in Shug Jordan's second year as coach.