Lehtonen turned aside all 20 shots he saw in the second period and 9-of-10 in the final period as the Canucks poured on the pressure.
Valeri Nichushkin and Erik Cole each scored for the Stars, who improved to 8-2-2 in their last 12 games.
Henrik Sedin scored on a third-period power play for the Canucks, who dropped a fourth straight contest.
Roberto Luongo made 21 saves.
Swim Week Miami Beach 2014 [PHOTOS]