Jackson-Davis and Phinisee (11 points) were among five Hoosiers (6-4, 1-2 Big Ten) to score in double figures as Indiana shot 57% for the game (32 of 56). Aljami Durham added 18 points, Armaan Franklin scored 16 and Trey Galloway had 10.
Penn State (3-4, 0-3) scored first in overtime on a layup off the jump ball and Myreon Jones twice gave the Nittany Lions either a one-point lead or a tie — the latter, 85-85, coming off a pair of free throws with 43 seconds left.
But as the clock was winding down, Phinisee hit his winner with 13 seconds remaining and Penn State, after a timeout, missed a shot at the buzzer.
Sessoms had a potential game-winning 3-pointer blocked by Phinisee in the final second of regulation. Phinisee also blocked a Sessoms jump shot with 42 seconds left in regulation and Indiana clinging to a one-point lead.
Penn State hosts No. 6 Wisconsin on Sunday, Jan. 3 while Indiana hosts Maryland on Monday, Jan. 4.