CHAPEL HILL, N.C. (AP) -- North Carolina's big early lead vanished, and coach Roy Williams was steamed. So, he yanked everyone off the court, sent in five subs and went ballistic on the bench.
"When Coach takes us out five at a time, we know we did something wrong," point guard Ty Lawson said. "He was cursing us out, basically."
Everyone got the message, and then everyone got involved in the scoring. All five starters reached double figures and the fourth-ranked Tar Heels scored 21 straight points during their 91-69 rout of Boston College on Thursday night.
"We got a lot of things from a lot of different people," forward Tyler Hansbrough said.
Hansbrough scored 18 points, Deon Thompson added 13 of his career-high 17 in the first half and Lawson finished with 16 for the Tar Heels (20-1, 5-1 Atlantic Coast Conference).
That big burst permanently turned the matchup of the league's top two scorers into a blowout and helped North Carolina reach the 20-win mark for the fourth straight year and 50th time in 98 seasons. Hansbrough entered leading the ACC with a 22-point average, with BC's Tyrese Rice two points behind.
Rice equaled his average with 20 points, but he was 6-for-15 from the field and 1-for-9 from 3-point range for the Eagles (12-7, 3-3), who had 17 turnovers and were denied their second straight victory at the Dean Smith Center. BC has lost three straight and five of seven overall.
"We turned the ball over way too much, myself included," Rice said. "We just can't do that on the road against a good team that likes to run up and down the court."
Lawson also finished with 10 assists and Alex Stepheson added 11 points for the Tar Heels, who returned to the dominant style that fans had gotten used to during their 18-0 start to the season. They were playing at the Smith Center for the first time since a surprising 82-80 loss to Maryland knocked them from No. 1.
"It feels a heck of a lot better than it did the last time we played here," Williams said.
Part of the problem for the Eagles was that their big men spent much of the night in foul trouble. Starting center Tyrelle Blair and backup Josh Southern both picked up a fourth foul early in the second half, and forward John Oates -- who was guarding Hansbrough -- fouled out with 10 1/2 minutes left. That left the inside open for the Tar Heels, who outrebounded BC 44-28.
"I'm smarter than to publically criticize refs, but some of the calls might have been a little tough," Oates said. "They're good enough, particularly Hansbrough, and then you have stuff like that. That made it a lot harder. We're having a hard enough time anyway."
Oates gave the Eagles their only lead of the game when he banked in a 3-pointer with 9:14 left in the half to make it 26-25. Thompson, who had 13 points in the first half, took the lead back for good 11 seconds later for the Tar Heels with his jumper from the free-throw line.
"We had the lead but it wasn't for long," Rice said.
North Carolina opened the game with a 14-4 run before falling into the lull that prompted Williams to make the mass substitution.
"I was ready to choke someone," Williams said.
The tactic worked: the Tar Heels scored the final 11 points of the half to take a 16-point lead and remove all doubt. After the break, the Tar Heels then picked up where they left off by reeling off 10 straight points, a decisive burst capped when Lawson blew past Rice for a layup that made it 57-31 with about 17 minutes left.
Lawson has combined for 20 assists and one turnover in the last two games.
"I'm just taking care of the ball a lot more, make sure the passes I make get through and not put the ball in jeopardy," Lawson said.