Blacksburg, VA -- (Sports Network) - Casey Barth kicked a 21-yard field goal as the clock expired, as North Carolina took advantage of an untimely fumble to upend 14th-ranked Virginia Tech, 20-17, at Lane Stadium.

Barth kicked two field goals inside the final three minutes, the second made possible by Virginia Tech freshman tailback Ryan Williams' fumble at the Hokie 28 just outside the two-minute mark. UNC ran Ryan Houston six consecutive times to gain the four and Barth banged home the game-winner from the right hash to give the Tar Heels (5-3, 1-3 ACC) their first conference win.

T.J. Yates threw for only 131 yards on 18-of-28 attempts but connected on a pair of clutch TD passes to Jheranie Boyd and Greg Little as North Carolina earned its first win over the Hokies since Virginia Tech started ACC play in 2004.

The Tar Heels had dropped from the rankings several weeks back following a winless start to their league schedule. This was the second consecutive Thursday night tilt for UNC, having lost a heart-breaker to Florida State at home last week 30-27.

Tyrod Taylor was 11-of-23 passing for 161 yards and managed to score on a pair of one-yard scores despite rushing nine times for negative eight yards.

Williams had a good game despite the costly fumble, rushing for 96 yards on 23 carries for the Hokies (5-3, 3-2 ACC), who were handed their second straight defeat.

Two weeks ago Virginia Tech was the No. 4 team in the country but tumbled down the standings following a 28-23 loss to then No. 19 Georgia Tech on October 17. Hokie nation had a week to stew on the loss with their bye last week.