Nico Gramatica nailed a 20-yard field goal as time expired as South Florida rallied to stun No. 13 Florida 18-16 on Saturday in Gainesville, Fla.

After beating then-No. 25 Boise State in Week 1, the Bulls (2-0) went 87 yards in eight plays in the final two minutes to set up Gramatica’s third field goal.

It was USF’s second straight win over an AP ranked team and first on the road since beating Notre Dame in 2011.

Gramatica missed a 58-yarder just short with 2:52 left that would have put the Bulls up.

USF signal caller Byrum Brown was 23 of 36 for 263 passing yards and a touchdown, while Florida’s DJ Lagway was 23 of 33 for 222 yards with a TD and an interception.

Florida kicker Trey Smack, who was 2 of 5 in last week’s 55-0 win over Long Island, booted a 28-yarder for a 3-0 lead on the first drive.

That score stood through the quarter, which ended with each team producing 86 total yards but with the Bulls in the red zone. Gramatica nailed a 38-yard kick on the second play of the second quarter to tie it.

After having two touchdowns taken off the board by penalties, Florida sent Smack out again and he banged home a 36-yard field goal at 7:13 for a 6-3 lead. At 1:50, Smack made it 3-for-3 by connecting on a 41-yarder.

However, the American Conference football team traveled 68 yards in eight plays, ending it with Gramatica’s 25-yard kick on the half’s final play for a 9-6 halftime deficit.

The teams traded series in the second half with the early highlight being James Chenault’s diving interception of Lagway over six minutes in.

The visitors stunned the crowd at the Swamp when Brown lofted a pass that Keshaun Singleton caught between two Florida defenders and raced to paydirt for a 66-yard tally for their first lead at 13-9 with 2:03 left in the third.

It got worse on the next Florida series when an errant punt snap sailed out of the end zone for a safety and a 15-9 advantage.

Lagway responded with a four-yard quick slant to Eugene Wilson III for a 16-15 lead early in the fourth quarter.