Sam Thompson also scored 13, while Aaron Craft added 10 points and 10 assists for the Buckeyes (3-0), who ended Marquette's 27-game home winning streak, second-longest in the nation.
It was the school's first loss at home since Vanderbilt beat the Golden Eagles 74-57 on Dec. 29, 2011. Only Middle Tennessee (30) had a longer home winning streak entering Saturday.
It didn't look like the Buckeyes could pull it off after shooting just 27 percent in the first half. But things opened up after halftime, when coach Thad Matta's team was 15 of 26 from the field (58 percent).
"Eventually, it's got to go in the basket," Matta said in recounting a halftime talk. "Fortunately we had that run."
Scott, Craft and Thompson were the sparks, while Marquette (2-1) came out flat in the second half in front of a full house of 18,700 fans in the BMO Harris Bradley Center.
The Golden Eagles had 20 turnovers and shot just 10 of 53 (19 percent) for the game.
No. 20 Wisconsin 69, Green Bay 66 • In Green Bay, Wisc., Frank Kaminsky scored 16 points and Sam Dekker added 13 to help Wisconsin rally past Wisconsin-Green Bay.
The Badgers (3-0) were down seven in the second half and 0overcame a career-high 32 points by Green Bay junior guard Keifer Sykes. His potential game-tying 3-pointer bounced off the rim at the buzzer.
• No. 9 Syracuse 69,Colgate 50
• No. 10. Ohio State 52,No. 17 Marquette 35
• No. 11 Florida 86,UALR 56
• No. 14 VCU 92,Winthrop 71
• No. 16 Wichita State 85, Tennessee State 71
• No. 20 Wisconsin 69, Green Bay 66
• No. 25 Virginia 70,Davidson 57