Gawanke cut hard for the slot before Heinola hit him with a centering pass before he slid the disc through Oscar Dansk's pads to give the Moose the win.
The goal was his 3rd of the season.
Cole Maier, Henri Nikkanen and Chaz Lucius scored for the Moose.
Ville Heinola had a pair of assists for Manitoba.
Oskari Salminen and Arvid Holm combined to turn aside 31 shots for the Moose, who moved to 7-3-1-0.
Emilio Pettersen scored twice for Calgary.
Cole Schwindt also scored for the Wranglers.
Oscar Dansk made 29 saves for Calgary, who dropped to 6-5-1-0.
With Calgary on a two-man advantage early on Cole Schwindt scored 5:16 into the first period, wiring a high wrister past Salminen to make it 1-0 Wranglers.
The goal was his 3rd of the season.
Emilio Pettersen made it 2-0 Wranglers at 10:23 when Connor Zary took a feed near the left corner and hit Pettersen with a crisp pass in the high slot.
Pettersen made no mistake, drifting a wrister and beat Salminen low glove side to score his 2nd goal of the season.
Cole Maier scored 1:13 into the second, golfing a puck past Dansk from the slot to make it 2-1.
The goal was his 3rd of the season.
Pettersen netted his second goal of the afternoon ten seconds later when he caught Salminen napping, scoring on a bobbling wrister from just outside the Manitoba blue line at 1:23.
Moose Head Coach Mark Morrison had seen enough and pulled Salminen in favor of Arvid Holm.
Heni Nikkanen got the Moose to within a goal at 7:23 when he took control of the puck just inside the Manitoba blue line and skated into the Calgary zone before snapping a wrister from the top of the right circle, beating Dansk blocker side to make it 3-2.
The goal was his 3rd of the season.
Chaz Lucius tied it with 42.4 seconds left in the second when he cruised in and knocked the rebound off a Simon Lundmark point shot past Dansk.
The goal was the 2nd of the season.
Manitoba visits Texas Friday while Calgary visits Bakersfield.
SHOTS-CALGARY 34 MANITOBA 33
ATTENDANCE-2945