Jamie Benn had three assists, Tyler Seguin had a goal and an assist, and Anton Khudobin made 28 saves for the Stars, who took a 1-0 lead in the Second Round series and suddenly look like an offensive powerhouse.
Nathan MacKinnon had two goals and an assist, and Gabriel Landeskog scored the othe Colorado goal and added an assist.
Philipp Grubauer allowed three goals on 10 shots before leaving 3:06 into the second period with an apparent left leg injury. He was replaced by Pavel Francouz, who made 18 saves.
Game 2 of the series is on Monday night.