Butler led the Blue Demons 73-62 with 3:20 remaining in the game, before DePaul went on an 11-0 run to force overtime.
The Blue Demons outscored Butler 12-7 in the 2nd overtime, shot 63.6% in the 2nd half and overtime, and used a decisive free throw advantage to put the Bulldogs away for their first win in Big East play.
DePaul shot 27/38 (71.1%) from the charity stripe, while Butler was just 20/32 (62.5%).
Kellen Dunham led Butler with 30 points, 28 of which came in the 2nd half and overtime. Dunham shot 9/25 from the field including 6/14 from three point range.
DePaul senior forward Cleveland Melvin led the team with 30 points (10/14 FG) for the Blue Demons and grabbed 8 rebounds.
Butler controlled play for much of the game. The Bulldogs led 35-32 at the break.
Four others were in double figures for Butler including Kameron Woods who finished with his 8th double-double of his career with 17 points (7/8 FG) and 14 rebounds.
Billy Garrett Jr. helped the Blue Demons get the win. The freshman guard scored 22 points, grabbed 5 rebounds, and dished out 5 assists.
In overtime, DePaul dominated play, but left open a chance for Butler and they seized it.
The Bulldogs trailed 84-78 with 29 seconds left in overtime when Kellen Dunham hit a jumper to cut the lead to just four.
DePaul then committed a turnover and fouled leading to two Butler free throws and just a two point lead, 84-82.
After two Garrett free throws, Dunham connected on a three and the lead was just one point 86-85.
Melvin made just one free throw for DePaul and Dunham raced down court, but missed a fall away jumper with 4 seconds left. A scramble ensued and it resulted in Jackson Aldridge grabbing the rebound and hitting a floater from the free throw line as time expired to force a second overtime.
Despite putting pressure on the Bulldogs all game, Butler turned the ball over just 11 times, while DePaul committed 18 turnovers.
DePaul shot 32/55 (58.2%) from the field including 8/14 (57.1%) from three, while Butler shot 34/71 (47.9%) from the field including 6/20 (30%) from three.
NOTES: DePaul had just a 40-38 advantage from the paint...Elijah Brown was 2/6 from the field and scored 4 points...Alex Barlow fouled out once again. He finished with 2 points and 5 rebounds...Attendance was 6,163.
It was over when...Kellen Dunham missed a three point attempt with 14 seconds left in double overtime trailing 98-94.
Stat of the Game: 63.6% - DePaul's field goal percentage in the 2nd half against Butler. Fueled by an 11-0 run to end regulation.