USC scored the game-winner with 0.2 left in the inaugural game at Dickies Arena.
The senior finished with a game-high 23 points.
The Frogs finish at 5-7 on the year, missing bowl eligibility by one win.
TCU failed to score in the last 7:39 of regulation.
TCU ended the game on a 24-7 run.
The guard hit a three with 3.3 seconds remaining to give the Frogs the win.
The Heisman Trophy candidate leads the Big 12 in total offense by over 50 yards.
The Frogs edged Air Force by 11 points Monday, their closest game of the season.
The Frogs were swept for the seventh time since the start of Big 12 play.
The Frogs just need one more win to reach bowl eligibility.