DURHAM, N.C. -- With every whistle, foul and trip to the free-throw line -- and there were plenty -- Alison Bales gave Duke some extra time to daydream about its biggest rival.
Bales scored 15 of her season-high 21 points in the first half and the top-ranked Blue Devils routed Clemson 105-53 on Monday night to remain perfect entering their showdown with No. 2 North Carolina.
"It's always fun to have a game like this," Bales said. "And what I mean by this is, the chest bumps, the fast breaks and everyone getting into it, scoring, sharing the ball really well. It's just good for team spirit."
Bales also matched a school free-throw shooting record, Carrem Gay scored 18 points and Abby Waner had 16 for the Blue Devils (24-0, 9-0 Atlantic Coast Conference).
Duke matched the Tar Heels' spotless record, and the Tobacco Road rivals play Thursday in Chapel Hill in a meeting of the last two remaining unbeatens.
"There's not a lot of time to prepare, so we need to continue to improve everything that we do," coach Gail Goestenkors said. "We know our rebounding is going to be key, we know our defense is going to be key, transition is going to be key, all the same keys that we had for everybody, except that we have to be better in every aspect of the game."
Wanisha Smith added 13 points for Duke, which shot 52 percent against one of the nation's worst defenses. The Blue Devils held a 51-23 rebounding advantage, surpassed the 100-point mark for the second time this season and clearly refused to look past the struggling Tigers (10-13, 2-6).
"We needed a game like this tonight," Goestenkors said.
D'Lesha Lloyd scored 14 points and Christy Brown added 12 to lead Clemson, which didn't get closer than 22 points in the second half and committed 20 turnovers against one of the nation's top defenses.
"If you play a great basketball team, and you lay down and die and don't play with any effort, you're going to get killed and embarrassed, and that's exactly what happened" after halftime, Clemson coach Cristy McKinney said. "They wanted the ball. They went [and] got the ball. We didn't do anything about it."
Duke won its 10th straight in the series. No previous Blue Devils team scored more points against Clemson.
Bales, who entered as a 72 percent free-throw shooter for her career, tied a school record by finishing 13-of-13 from the foul line. She joined nine other players in school history, most recently Monique Currie, who were perfect on at least 10 attempts.
"I made my free throws, so that was really what helped my points," Bales said. "My free-throw percentage was a little lacking."
She surpassed her previous season best of 18 points set in the win over Maryland which catapulted the Blue Devils to No. 1, and fell one point shy of her career-best 22 set against Southern California in the second round of last season's NCAA tournament.
The 6-foot-7 Bales took advantage of the smaller Tigers' knack for fouling early in this one. She drew two fouls in three minutes on Clemson center Moreemi Davis, who then spent most of the half on the bench, leaving Bales free to dominate the low post.
Clemson's game plan "sure wasn't, 'Foul her every time she touches the ball,' which is about what we did," McKinney said. "I thought we helped her early, because every time she touched it, we smacked her."
Bales -- at least 3 inches taller than any Clemson player -- entered as the nation's leader in blocked shots, averaging 4.7, and she swatted away three attempts by the Tigers. She also had a perfect first half, hitting all three of her shots and all nine of her free throws while committing no turnovers.
Duke led comfortably for all but a 4-minute stretch, and the Blue Devils took complete command with a 19-2 burst late in the first half. The punishing 5 1/2-minute stretch ended when Waner's 3-pointer from the left corner made it 48-25 with 2:03 left.
The Blue Devils scored a season-high 54 points in the opening 20 minutes.