Sharks forward Zack Ostapchuk appeared to tie it 1-1 at 15:28 when he deflected a point shot from Timothy Liljegren under Oettinger's glove. However, the goal was overturned after an official review determined Ostapchuk's stick hit the puck above the crossbar before going in.
Johnston made it 2-0 at 17:38 after taking a cross-ice pass from Miro Heiskanen and burying a wrist shot from the slot over Nedeljkovic's glove.
Mukhamadullin cut the deficit to 2-1 at 1:43 of the second period. Ty Dellandrea won a face-off back to Mukhamadullin, who sent a wrist shot from above the left face-off circle that deflected off the right skate of Dallas defenseman Ilya Lyubushkin and through Oettinger's pads.
Johnston scored his second goal on the power play at 8:40 to push the lead to 3-1. Rantanen one-touched a pass from Hintz to Johnston in the low slot, where he put a snap shot over Nedeljkovic's right shoulder.
"It's great. It's not the easiest League to score in. Just trying to get to those spots and keep shooting the puck," Johnston said. "It's awesome playing with some awesome players who can get you the puck when you're open."
Graf made it 3-2 at 16:44. Celebrini sent a pass from the left corner to Graf in front, and after his first attempt rebounded off Oettinger, he put the second shot in past the left pad.
"It was a set for him to go forward there, and I was just trying to go to the back post," Graf said. "I just sort of stayed there because he still had the puck."