Nevada blew a 15-point second-half lead and watched Idaho take a five-point lead before bouncing back in the final minutes to stave off the conference loss.
Johnson buried a 3-pointer with 19 seconds left to tie the game at 64-64, but Idaho regained the lead when Mac Hopson canned a pair of foul shots with 6.2 seconds to go.
Johnson, Nevada’s point guard, caught the ensuing in-bounds pass on the move and drove the length of the floor. He got a runner to bounce around the rim and fall through the twine. He also drew a foul on the sequence. The Reno native made the corresponding free throw to put Nevada on top.
Idaho got off a deep, contested three-point try but it missed, icing the win for the visiting Wolf Pack.
It looked like Nevada would romp early in the second half. The Wolf Pack got a runner from Luke Babbitt less than four minutes after halftime. The bucket saw Nevada forge ahead 49-34.
Unfortunately for Nevada, it managed just five points in a span of more than 11 minutes. During that same stretch, Idaho reeled off 23 points. The last of those came on a Kyle Barone hook shot that left the host Vandals clinging to a 59-54 edge at the 4:59 mark of the second half.
Offensively, Nevada was red hot in the first half. The Wolf Pack connected on 8-of-11 shots from 3-point land in the first 20 minutes. The torrid shooting helped the Pack grab a 42-28 halftime lead.
The margin was six, 34-28, with two minutes left before halftime, but Nevada responded by scoring the final eight points before the intermission to take control.
Johnson finished with 23 points and Babbitt chipped in 21 for Nevada, which improved to 14-9 overall and 6-4 in the WAC.
Hopson led Idaho (11-12, 3-8) with 17 points.
Nevada returns to the hardwood Saturday for a home game against Boise State. Tip-off is 7:05 p.m.