CHARLOTTE, N.C. (AP) _ Before North Carolina took the court against Washington State and its deliberate offense, Roy Williams scribbled a message about defense on the board in the locker room.

"Tough enough, patient enough, poised enough," it read.

His Tar Heels were all three. Now they're within a game of the Final Four again.

Tyler Hansbrough scored 16 of his 18 points in the second half and the top-seeded Tar Heels held Washington State to 32 percent shooting in a 68-47 victory Thursday night, sending North Carolina to the NCAA tournament's round of eight for the second straight season.

Danny Green had 15 points to help the Tar Heels (35-2) set a school record for victories while continuing their dominant run through the East Regional. The No. 1 overall seed has won its first three NCAA games by 20 or more points for the first time in program history as it chases a record 17th trip to the Final Four.

"We continued to talk about this throughout the year, the fact that we're tired of hearing that North Carolina can't play defense and that's going to be our weak link," junior Marcus Ginyard said. "But tonight, I think you see that this team has the capability of buckling down and being that great defensive team."

All season, Williams never stopped pushing his team to play better defense, not even as it piled up lopsided wins and crowd-pleasing offensive displays that few teams could match. Against a fourth-seeded Cougars team that had completely shut down its first two tournament foes, the Tar Heels gave their Hall of Fame coach what he had been asking for since November.

North Carolina played patiently and didn't take chances as the Cougars' offense ate into the clock. Washington State (26-9) managed just 18 field goals for the game while scoring 20 points below its average and going 2-for-16 from 3-point range. The 47 points were the fewest allowed by the Tar Heels in an NCAA game since 1946.

"I said to Marcus and Danny and Wayne (Ellington), 'You're going to be hit by a screen. You have to be tough enough and patient enough to get through it,'" Williams said. "'You've got to be tough enough and patient enough to continue to play the defense for 35 seconds.'"

When it was over, North Carolina had advanced with a very un-UNC-like score to play third-seeded Louisville, which beat Tennessee 79-60.

In Thursday's other games, Xavier beat West Virginia 79-75 Thursday to advance to the West Regional final against No. 1 seed UCLA on Saturday. The Bruins beat upstart Western Kentucky 88-78.

North Carolina improved to 24-1 in NCAA games played in its home state and is 7-0 all-time in Charlotte Bobcats Arena. Now they can focus on erasing the lingering memories from last year's final game: a blown double-digit lead late in the second half of an overtime loss to Georgetown in the regional finals.

"We know what happened. We know that feeling," Hansbrough said. "We don't want to have it again. That's kind of our attitude, and that's the mentality we have."

For the first time in this tournament, the Tar Heels, the nation's second-highest scoring team, didn't crack 100 points. It didn't matter. Nor did it matter that Hansbrough struggled much of the way. After hearing all about how Washington State held Winthrop and Notre Dame to a combined 81 points, the Tar Heels looked determined to prove they could play some tough defense, too.

Washington State missed shot after shot sometimes open, more often not while the Tar Heels kept pushing forward with their slowed, but effective, transition attack. The Cougars got little from the perimeter, with Kyle Weaver and Taylor Rochestie scoring a combined 12 points on 4-for-21 shooting.

"It was freezing out there," said Weaver, who had 10 points.

Derrick Low and Aron Baynes scored 14 points to lead the Cougars.

Meanwhile, the Tar Heels kept the pressure on, gradually getting more runouts in transition and increasing the pace to steadily build the lead. North Carolina led 35-21 at halftime on a 3-pointer from Ty Lawson just before the horn, then got a quick six-point burst to push the lead to 47-27 on Alex Stepheson's three-point play with 11:45 left.

"We've played some really good teams in our league with some different styles," Washington State coach Tony Bennett said, "but North Carolina is very special."

Copyright 2008 The Associated Press.