Johnson scored on short runs in the second and third quarters for the Panthers (3-1, 2-0 Missouri Valley Conference). Tirrell Rennie added 209 passing yards, including a 26-yard touchdown to Jarred Herring.
The Bears (0-5, 0-2 MVC) got their only score on quarterback Trevor Wooden's 5-yard run early in the second quarter. That tied the game 7-7, but it was all Northern Iowa after that.
Chad Owens had a 7-yard touchdown run for the Panthers' first score, and backup quarterback Jared Lanpher found Kevin Vereen from 11 yards out to cap the scoring late in the fourth quarter.
Wooden completed 18 of his 21 passes for 134 yards and one interception, returned for a touchdown by Varmah Sonie with 4:53 left in the first half.