The Bulls had been limited to 31 yards rushing entering the fourth quarter.
Blake Barnett went 12 for 20 for 181 yards and one touchdown for USF (4-0). He also ran for a 2-yard score.
ECU (1-2) used two quarterbacks. Reid Herring completed 21 of 48 passes for 253 yards and Holton Ahlers picked up 48 yards on 12 rushes while completing 1 of 2 passes for 3 yards.
Barnett hooked up with Darnell Salomon for a 66-yard TD pass and a 13-7 lead early in the second.
Jake Verity had a 28-yard field to make it 13-10 as the first half ended. The kick came two plays after Herring walked gingerly off the field following a 5-yard to run to the 5 with 15 seconds left.
Herring retuned for the Pirates initial second-half possession.
After forcing a turnover, ECU pulled to 13-all on a 24-yard field goal by Verity early in the third quarter.
Ahlers scored on a two-yard run as East Carolina opened the game with a nine-play, 82-yard drive.
USF got within 7-6 on Barnett’s two-yard dash late in the first. The extra-point try was blocked.
THE TAKEAWAY
East Carolina: The Pirates kept it close through the third quarter using a ball control offense that outgained USF 305-199. ECU had the ball for more than 29 minutes, running 69 plays compared to the Bulls’ 40, going into the fourth quarter.
South Florida: The Bulls remained, along with No. 16 Central Florida (3-0) and Cincinnati (4-0), among the only undefeated teams in the AAC. All three are in the East Division. The Bulls play at Cincinnati, which rallied from a 24-7 halftime deficit Saturday to beat Ohio 34-30, on Nov. 10th
NUMBERS
Barnett has eight touchdown passes and ran for four more this season. . Solomon has caught a TD pass in three consecutive games. . It was the Bulls 150th win, coming in their 22nd season. . Verity has made all of his seven field-goal attempts this season.
UP NEXT
East Carolina: Closes out its non-conference slate Saturday at home against Old Dominion (1-3), which upset Virginia Tech 49-35 Saturday.
South Florida: Plays its last non-conference game after an off week Oct. 6th at UMass (2-3).