Callahan added four steals while Tarrant had five assists. Josh Davis had 11 points and eight rebounds for the Green Wave (7-2).
Freshman T.J. Carpenter notched a career-high 15 points for the Colonels (1-4).
The win makes Tulane 4-0 on its current homestand, and the Green Wave has now won 19 of 20 all-time showdowns with Nicholls State.
Tulane led 23-12 with just under 8 minutes left in the first half, but the Colonels cut the lead to 30-24 by halftime.
Callahan hit a 3 then Davis made a dunk and two free throws to put Tulane up 37-24 after the break. Nicholls State never pulled closer than eight after that.
Forward Kennedy Meeks, who has averaged 9.4 points and 6.5 rebounds at North Carolina, has pulled out of the NBA draft and will return to the Tar Heels.
Cal big man Ivan Rabb could have been selected in the top 10 of the NBA draft. Instead, he's returning to Berkeley to make himself, and the Golden Bears, stronger.
Devin Williams' decision last month to sign with an agent and enter the NBA draft has left West Virginia in a tough spot.
|Stephen F. Austin||18-0||-||28-6|
|Sam Houston State||12-6||6||18-16|