Kahun made it 1-0 at 7:29, scoring from the goal line after Bishop committed a turnover behind the net.
"They dumped it in and I went to go play it and accidentally kind of hit it backwards while I was trying to hit it forward," Bishop said. "The guy made the play up front. It's an unfortunate play, but sometimes it happens."
"It's great for Dominik," Penguins coach Mike Sullivan said. "We felt like he's been around it the last handful of games. He's had a lot of chances and the puck hasn't gone in the net for him. It's a big one for us tonight."
Rust scored on a wraparound when the puck deflected off the foot of Stars defenseman John Klingberg to make it 2-0 at 9:07. Rust, who sustained an upper-body injury in Pittsburgh's preseason finale Sept. 28, was making his season debut.
"Rust brings that speed dimension," Sullivan said. "He's hard to play against. He forces turnovers and he wreaks havoc with his speed."
Tanev scored into an empty net at 18:46 for the 3-0 final.
The Stars went 0-for-2 on the power play and are 3-for-36 (8.33 percent) with the man-advantage this season.
"The power play to me was just a lack of effort, especially the second one," Montgomery said. "I thought the effort was there on the first one except for one moment. On the second, we were just disjointed. That's unfortunately been the story for our power play for the season so far."
"You have to read off of each other and read off where the puck is going," Klingberg said. "You've got to move together. At the same time, it comes down to winning those one-on-one battles and getting the puck up and creating movement from there. I think right now we are sometimes throwing the puck away when we don't have to. It's frustrating and it's something that we have to work on."'