North Carolina produced mostly a splendid regular season and one of the glitches during the past two months came against Louisville.
The third-ranked Tar Heels later avenged that result, and now the teams will play for a third time in the Atlantic Coast Conference tournament.
They meet Thursday night in the quarterfinals at the Spectrum Center in Charlotte, N.C.
Seventh-seeded Louisville trounced 12th-seeded Notre Dame 75-53 in Wednesday night's second-round game.
When Louisville defeated North Carolina 83-62 on Jan. 12 in Chapel Hill, it spurred the Tar Heels to refocus and nearly go unscathed since then.
It also might be the reason that North Carolina stayed under the radar for a chunk of the winter.
"I really don't get into that," coach Roy Williams said about whether his team has been underappreciated. "The bottom line for us is to have great kids and win and I think we've done that."
Indeed, North Carolina (26-5) ended up as a co-champion in the ACC regular season and holds the No. 2 seed as it opens tournament play.
North Carolina avenged the loss to Louisville by defeating the Cardinals 79-69 on the road Feb. 2.
The Tar Heels have one loss in their last 15 games.
"We are feeling good right now," North Carolina guard Cameron Johnson said. "We understand that right now it is win or go home. You cannot take anything for granted this time of year."
North Carolina had to defeat Duke in Saturday night's regular-season finale to claim a share of the regular-season title.
It's the ninth time in 16 seasons as North Carolina coach that coach Roy Williams has overseen a regular-season title of some sort. In each of those nine seasons, the Tar Heels won the regular-season finale against Duke to secure either the outright championship or a partial title.
North Carolina has reached the ACC Tournament's final in three of the last four years, winning it once.
Louisville (20-12) has reached the 20-win mark in coach Chris Mack's first season.
After the Cardinals defeated North Carolina, they entered the national rankings. They were still as high as No. 15 for the rematch.
"We know that we have a huge challenge in the Tar Heels," Mack said. "But it beats going home."
North Carolina entered the week leading the country in rebounding with 43.9 per game.
"When you play a team for a third time, both teams are going to have great familiarity with one another," Mack said. "Coach Williams doesn't try to trick you. They're going to try to race the ball up the floor. They're going to try to pound it inside, and they're going to try to decimate you on the glass. They did that in (the second meeting this season)."
North Carolina senior guard Kenny Williams racked up a season-high 18 points in the most-recent Duke game. That could be a good omen as freshman point guard Coby White is bound to be receiving more defensive attention as his point totals have soared recently.
"I just needed to see the ball go in," Kenny Williams said.
The Louisville-North Carolina game is the opener of a night session doubleheader.
"It's going to be obviously pro-Carolina," Mack said of the crowd. "I'm hoping the Duke fans (waiting for the nightcap) get excited, too, for the Louisville Cardinals."
--Field Level Media