Gatherings were mostly peaceful Monday night following Louisville's 82-76 victory — the school's third title, and first title since 1986. Louisville police said most of the 23 arrests were due to drunken or disorderly conduct.
Hundreds streamed onto Cardinal Boulevard after Louisville's win, screaming, dancing and lighting off small fireworks in revelry that lasted into the early hours.
But things got out of hand as the celebration was winding down early Tuesday, with police in riot gear and an armoured car arriving after large, unruly crowds refused to disperse.
Several scuffles followed and some partiers threw bottles at police, hitting an officer in the head, said police spokeswoman Carey Klain. The officer received minor injuries and was treated at a hospital and released, Klain said. Police responded to the bottle throwers with pepper spray.
A few revelers received minor injuries, said University of Louisville spokesman John Drees. He said two were injured in falls and another suffered a cut foot.
The citywide party could be repeated Tuesday night if the Cardinals' women's team beats Connecticut for the NCAA championship in New Orleans.
"It's huge," said freshman Paul DeNeve. "We have not only won tonight but the women's team plays tomorrow."
For now, though, fans are savoring the Cardinals' men's achievement.
"This means everything," said Connor Millay, 19, a Northern Kentucky University student who travelled to Louisville despite facing two tests Tuesday.
"I've been waiting for this my whole life," Millay said. "My dad experienced this. My grandpa experienced this. I needed one of these."
Elsewhere around town, Cardinals faithful partied in dormitories and around campus, in bars and restaurants and in living rooms after Louisville claimed its third national championship.
Most chose the quiet comforts of home over the noisy crowds that assembled in the Fourth Street Live! entertainment district. But when Louisville emerged victorious at the Georgia Dome in Atlanta, emotions were felt everywhere.
"We've been waiting for this for the past 27 years," said Joe Barnes, 61, a University of Louisville alumnus who walked among the thousands of students on Cardinal Boulevard. "This has been one of the best teams that U of L has had. Ever. They've showed more spirit, more hustle. They believe in each other."
The men's championship was a nervous watch for Louisville's fan base, which saw the Cardinals trail by 12 in the first half before rallying to 38-37 at the break. Louisville eventually went ahead and led by 10 in the second, withstanding Michigan's attempts to come back.
Krissy Van Laan and friend Lindsay McDaniel had their spots at the Ri' Ra' Irish Pub, staying all the way through and witnessing the mayhem that unfolded immediately afterward.
"Everybody was so excited. It was unbelievable," Van Laan said. "Once it got down to four seconds left, I knew we had it. People were running out in the streets and excited. This is just unbelievable."