The win was the second straight for the Razorbacks, who survived the hot-shooting Tigers and guard Frankie Sullivan's five second-half 3-pointers.
Young added 22 points and Mardracus Wade had 12 for Arkansas (11-5, 2-1 Southeastern), which now has won seven of its last eight games. Powell had 21 points in the second half and overtimes, finishing with his second-highest point total of the season.
Sullivan led Auburn (8-8, 2-1) with 26 points, 23 of them after halftime. He was 5 of 11 on 3-pointers, and the Tigers were 11 of 25 overall from behind the arc.