Each team took a trio of shots in the first half, but neither found the back of the net in the opening 45 minutes.
Warhol's goal came as he sat with plenty of time at the top of the box, scoring on a hard shot to the left side of the net at 64:09. Dave Donner (Jr., Stillwater, Minn.) had the assist.
The goal was Warhol's third of the season.
Zach Nelson (So., Eagan, Minn.) had three saves in the game and the Pipers fended off a Johnnies' offensive flurry of activity in the final minute for the shutout.
With their first conference win of the season the Pipers move to 5-7-1, 1-3-1 MIAC. The Johnnies fall to 4-6-0, 1-4-0 MIAC. Hamline will return to play in one week when they host Concordia on Wednesday, October 14, at 1:30 p.m. The game will be the first in a men's-women's double-header.
For post-game reaction from Warhol and head coach Jon Lowery, click here.