Luke Davis, Desmond Hubert, Jackson Simmons and J.P. Tokoto joined Marcus Paige in replacing Dexter Strickland, Leslie McDonald, Brice Johnson, Reggie Bullock and James Michael McAdoo after the momentum had swung back in the Wolfpack's favor.
N.C. State had connected on 5-of-7 shots after falling behind 40-30 less than three minutes into the second half.
The 10th-year UNC head coach's message to the bench following the substitution was brief and to the point, according to P.J. Hairston.
"If you want it, you have to play."
Williams went with a similar approach, although not quite as dramatic, in North Carolina's loss in Raleigh last month. Davis, Tokoto and Simmons played for several minutes together as Williams sent a message to his starters. The result? UNC outscored N.C. State by 15 over the final 10 minutes at PNC Arena.
"I was just ticked off," Williams told reporters following Saturday's 76-65 victory. "I thought we were getting lackadaisical and casual with everything we did. We hadn't gotten picked up twice in a row and we turned it over two out of three possessions and one of them we were fortunate that we collected the ball, but we really made a bad play."
His players understood the move.
"It was a stretch where we just weren't playing hard at all," Hairston said. "We weren't fighting through screens and that's exactly how Scott Wood got those two wide open shots. We checked back in after the media [timeout] and he told us, ‘This is it - you have to play from here on out and get stops.'"
That was a critical reminder, according to Paige.
"It was like, ‘Hey, just because we won the first half doesn't mean anything. We still need to come together and finish this game out,'" the freshman point guard said.
The starting five reunited following the second media timeout with 11:37 to play as UNC trailed 49-45. What followed was a 25-8 run - fueled by 12 of Reggie Bullock's game-high 22 points - that gave the Tar Heels a 70-57 lead with 3:37 to play.
"I do think when those guys came back in they had a better sense of purpose," Williams said. "That's probably the biggest thing we got out of it."
One critical stretch occurred with 8:06 remaining. N.C. State led 55-52 and promptly committed four turnovers and missed three of four shots over its next seven possessions. UNC, on the other hand, made all three of its 3-pointers and all six of its free throws during that stretch.
"Those [were] four minutes right there where we had some empty possessions," N.C. State head coach Mark Gottfried said. "They, in turn, took advantage of that and knocked down a couple of key threes. That little stretch right there I thought was the difference in the game."
As for those groans throughout the Smith Center? They shifted to thunderous cheers as North Carolina topped N.C. State for the 20th time in 22 meetings.