The only bigger comeback in NCAA history came in 2012, when BYU beat Iona after trailing by 25 points.
The Wolf Pack's only lead of the game came with 9.1 seconds remaining when Josh Hall hit a short jumper that would hold up as the final score. Nevada never allowed the Bearcats to get another shot up in the final 9 seconds to seal the comeback victory.
Cody Martin led Nevada's furious rally by collecting 25 points, six rebounds and seven assists with no turnovers. The Wolfpack got to work from there and tied the game on a Caleb Martin three-pointer with 54 seconds left. Cane Broome briefly lost control of the ball and then passed to the area of Gary Clark as the final seconds ticked away.
Nevada trailed by 14 in the second half of their first-round game when they forced overtime and beat Texas.
Nevada (29-7) will play No. 11 Loyola Chicago on Thursday in Atlanta in the Sweet 16.
Cincinnati held a 22-point lead at one point in the second half and then went ice cold from the field, going on a field goal drought that would last 4 minutes, 51 seconds.
That stood up as the game-winning bucket.
The Orange fouled intentionally to avoid giving up a game-tying 3 twice in the closing seconds and the Spartans made two pairs of free throws to pull within a point both times. The Bearcats had no trouble in a 15-point opening-round win against 15th-seeded Georgia State, and for a while, it looked they looked like they'd have a walk to the Sweet 16.