Now this is madness.

Four games in the NCAA tournament went to overtime Thursday night, setting a record for one day, according to STATS.

The last of the 16 games on Thursday — New Mexico State against San Diego State — produced the fourth and final OT.

Before that, North Dakota State upset Oklahoma in overtime at Spokane, Wash. Saint Louis rallied late to force OT and beat North Carolina State in Orlando, Fla. The first overtime game came in Buffalo, N.Y., where Connecticut beat Saint Joseph’s.

The final game of the First Four also went to overtime Wednesday night, when Tennessee beat Iowa. That means five of the first 20 games in the tournament, a thrilling 25 percent, have extended into an extra 5-minute session.