Thomas Greiss (34 saves) held the fort in the opening 10 minutes, but Dallas opened the scoring at 11:59 of the first period, as Cogliano redirected a Jamie Oleksiak centering feed past the Isles netminder.
Dallas extended their lead to 2-0 before the end of the period, as Radulov threaded a wrister through a screened Greiss at 16:02. Radulov, who was scratched for Dallas' 3-2 OT win over Winnipeg on Thursday, finished the night with a game-high two points (1G, 1A).
Gurianov made it 3-0 at 3:12 of the second period, as he deflected a Radulov feed past Greiss for the Stars' second power-play goal of the night.
"They do a real good job of keeping pucks to the outside and you really have to will yourself in there," Trotz said. "They've got some dynamic offensive guys and they are a veteran team. They're big, they can skate. They have good goaltending. They're going to be a threat forsure. They are a good hockey team."
After generating a host of chances in a run-and-gun game vs the Golden Knights on Thursday, the Isles had trouble generating extended zone time, or secondary opportunities on Saturday, albeit against a stingy Stars team. The Isles did manage to outshoot the Stars 14-8 in the third period and Barzal eventually broke Bishop's shutout bid late, deflecting a Devon Toews point shot at 15:27 for his team-leading 12th goal of the season.
"It wasn't a terrible game by any means, we did some good things," Josh Bailey said "I thought we came out on the wrong end of the first period when it could have went the other way, but they have a good team over there."
"We couldn't quite find a way to rally and come back. Just too little, too late," Bailey added.