The Tar Heels, who won for the eighth time in their last nine games, held onto their share of first place in the conference by improving to 10-2 in ACC play.
They will put their 23-4 record on the line against North Carolina State in Raleigh in their next outing.
Williams said he believes his team has been giving a good effort at the defensive end all season, but now is beginning to see the fruits of those labors.
"Even earlier I thought we were trying," he said. "We had the intensity earlier. We just weren't proficient at it. I think that our guys are just more in tune with our defensive principles right now.
"Defense is not just effort. You've got to know what you're doing. It's something I am proud of, and I think our guys are getting better." The players agreed.
"It's kind of habitual now, just because I've played so much in the system," junior forward John Henson said. "Getting your hands on the ball, being in the right position, that's the type of things that the defense does.
"You build habits in practice, and it's kind of a habit now. And we just have to keep getting better on defense."
Sophomore Kendall Marshall had only four points in North Carolina's win over Clemson, but he handed out 13 assists, reaching double figures in the category for the 11th time this season and 17th time in his career.
"I've got to give full credit to my teammates," Marshall said. "They did a great job of getting to the back of defender's heads and making it an easy passing lane.
"When you have players like John sitting at the rim, you have no choice but to throw it to him."
That would be 6-11 F John Henson, who had 13 points against the Tigers.
With four games left in the regular season, Marshall has 262 assists, third most in North Carolina history with first place well within reach. Ed Cota has the first two spots on the single-season list with 284 in 1999-2000 and 274 in 1997-98.
-- Sophomore F Harrison Barnes has been both more assertive and productive in the last two games. After taking a season-high 19 shots and scoring 23 points in the mid-week win over Miami, he came back with 18 field-goal attempts and 24 points against Clemson.
He led the Tar Heels in scoring in each of the two games.
-- Coach Roy Williams now has 666 wins in his time at Carolina and Kansas, 23rd-most all-time. No. 22 on the list is Gary Williams, who retired after last season with 668 wins at Maryland, Ohio State, Boston College and American U.
BY THE NUMBERS: 56-0 -- North Carolina has yet to lose at home to Clemson in 56 games in Chapel Hill. That includes 24 wins in the Smith Center, the Tar Heels' current home.
QUOTE TO NOTE: "The shots were just falling. My teammates did a great job finding me. Kendall, with the shot clock winding down, was able to find me, and I was able to capitalize." -- Sophomore F Harrison Barnes, crediting G Kendall Marshall, among others, for his big game (24 points) against Clemson.
STRATEGY AND PERSONNEL
THIS WEEK'S GAMES:
--at North Carolina State, Feb. 21
KEY MATCHUPS: F Scott Wood with 11 points was the only player in double figures for N.C. State the first time these rivals met in Chapel Hill on Jan. 26. F C.J. Leslie had eight rebounds for the 'Pack, who were no match for Carolina's Tyler Zeller (17 rebounds) and John Henson (10) inside.
--at Virginia, Feb. 25
KEY MATCHUPS: The Tar Heels overwhelmed the Cavaliers in the second half, pulling away from a three-point halftime lead to a 70-52 victory when the two teams played in Chapel Hill on Feb. 11. F Mike Scott scored 18 points and G Jontel Evans added 12, but no other player managed more than eight points for Virginia.
FUTURES MARKET: North Carolina is still adjusting to the loss of G Dexter Strickland to a season-ending knee injury. Sophomore Reggie Bullock has moved into the starting lineup in Strickland's place, which means coach Roy Williams has had to go a bit deeper in his bench than he had hoped. The Heels lost one guard, Leslie McDonald, to injury before the season even started. Freshman P.J. Hairston has hit a shooting slump, putting more of a load on little-used senior Justin Watts.
"It's a struggle for us, there is no question," Williams said of the position. "But it is what it is. You've got to play and keep fighting and keep fighting."
-- Sophomore G Reggie Bullock went 3-of-5 from 3-point range against Clemson, his most 3-pointers since he made three against Georgia Tech on Jan. 29.
-- Senior F Tyler Zeller bounced back from a nine-point game against Miami in the middle of the week to score 14 against Clemson for his 11th time in double figures over 12 games.
-- Junior F John Henson had three blocks against Clemson to give him 263 blocked shots in 101 career games. His average of 2.6 per game is a school best.