UNC (30-6) will face No. 5-seeded Southern California, second-round winners over Texas, on Friday night in East Rutherford, N.J.
During a TV timeout with 12:33 left in the first half, Hansbrough returned to the court without the protective mask he had worn in four previous games after suffering a broken nose via the now infamous flagrant elbow thrown by Duke's Gerald Henderson.
"I was happy when he took it off," Roy Williams said, "because I thought psychologically that would give him a little bit of a boost."
With his team under the threat of a season-ending loss, Hansbrough took the Tar Heels on his back converting 10-of-17 field goal attempts to go with 13 free throws.
"I think movement was the key for me tonight and my teammates gave me the ball inside which I felt comfortable with," said Hansbrough, who has scored more points just once in his college career, when he set an ACC freshman scoring record 40 points versus Georgia Tech last season.
Dominant as they were, Hansbrough's statistical totals didn't overshadow a 20-point, eight-assist and one-turnover night for Ty Lawson; nor did it cause Reyshawn Terry's 14-point performance which included more clutch scoring down the stretch to be overlooked.
"It was great basketball to get the ball in there to Tyler; Tywon did a great job of penetrating and when it got to crunch time, Reyshawn decided he wanted his senior season to continue," Williams said.
The Tar Heels are now 4-0 versus Michigan State in NCAA Tournament play.
The Spartans (23-13) might have been wearing the green while gunning for a St. Patrick's Day upset, but when the game was on the line, it was the Tar Heels that came up money. Facing a 57-54 deficit with 8:48 left in the game, the Tar Heels outscored MSU 27-10 the rest of the way.
Wielding a reputation for physicality, Michigan State relied heavily on its leprechaun-like point guard Drew Neitzel, who scored 26 points. But by the time the final buzzer sounded, all the head-shaven junior could do was catch his breath and ice down his shooting arm following 9-for-27 shooting performance.
"We just wanted to keep fresh bodies on him and make him work for everything he got," Wes Miller said of UNC's defensive plan on Neitzel. "He's a tremendous player and he hit some tough shots, but our job tonight was to make him earn them."
Neitzel – the Spartans' undisputed offensive leader – misfired on 11 three-point attempts and coughed up four turnovers. He was hounded for 38 incessant minutes by Lawson, Miller and Quentin Thomas, along with 6-6 swingman Marcus Ginyard.
"He's a big-time player," Ginyard said. "We feel like we just wore him down."
MSU coach Tom Izzo agreed he had never seen a defensive onslaught of personnel like the Tar Heels put on Neitzel.
"I just didn't have another guard I could put in," Izzo said. "Drew was walking on his knees."
The battle of the boards was a major pre-game concern for Williams, and Carolina out-rebounded the Spartans, 40-29. But it was the Tar Heels' second-half defense that gained the applause of their fourth-year head coach. UNC shot 50 percent over the game's final 20 minutes, while holding MSU to 33 percent shooting after the break.
"People talk about their rebounding – they're ranked fifth in the nation, but we're ranked third," Williams said. "Our kids showed a tremendous amount of toughness today. We can say that we've played 36 games and these guys are no longer freshmen and sophomores, but it is the first time half of our team has gone through this. From a maturity level I think it gets better every single day."