Johnson scored 19 points and grabbed 17 rebounds Sunday, leading the No. 2 Tar Heels over Virginia Tech 75-70 for its 12th straight victory.
With No. 1 Oklahoma losing to 19th-ranked Iowa State this week, North Carolina (18-2, 7-0 ACC) could find itself back atop the poll Monday, a spot it held at the beginning of the season but quickly lost.
Roy Williams earned his 350th victory with the Tar Heels and a unique place in basketball history, becoming the first NCAA coach to win at least 350 games at two Division I schools. He won 418 games at Kansas before joining North Carolina in 2003.
North Carolina, which is off to its best start in the conference since the beginning of the 2000-01 season, led by as many as 20 in the first half. The Tar Heels were up 57-49 with 11:01 remaining but the Hokies went on a 12-2 run and took a 61-59 lead on a basket by Kerry Blackshear Jr. with 8:05 remaining. It was their only lead of the game.
Seth Allen made two free throws with 19.2 seconds left for the Hokies (12-8, 4-3) to pull to 72-70, but Marcus Paige hit two free throws with 17.8 seconds remaining to push the lead back to four.
After Virginia Tech's Justin Bibbs missed a 3-pointer with 8 seconds to go, the Tar Heels' Johnson made one of two free throws with 6.5 seconds remaining for the final margin.
Zach LeDay led the Hokies with 17 points. Jalen Hudson added 14.
Six of Johnson's 17 rebounds came on the offensive end. The Tar Heels had 20 offensive rebounds and scored 18 second-chance points. North Carolina outrebounded the Hokies 48-33.
North Carolina's rebounding helped offset a day when the Tar Heels shot 37.8 percent (28 of 74) and made just 3 of 23 from beyond the 3-point arc. They have now shot worse than 40 percent from the floor in three straight games.
Berry II added 13 points for North Carolina, but made just 5 of 17 from the floor.
North Carolina: Led the ACC and ranked second in the nation in scoring offense coming into this game (86.2 ppg). ... The Tar Heels have won six straight against the Hokies. ... Johnson recorded his 11th double-double of the season and the 21st of his career. ... Berry II has scored in double figures in 11 straight games and in 17 of the Tar Heels' 20 games this season.
North Carolina: is at home against BC on Saturday.