Gonchar had a power-play goal, his second score this season, with just under 5 minutes remaining in the first period against his former team. Dallas has scored with a man advantage in seven consecutive games.
Alex Goligoski, another former Penguins player, had an assist when Benn scored to make it 2-0 at 3:14 of the second. Peverley closed the scoring a little more than 7 minutes later.
Lehtonen faced only 12 shots during the first two periods, before the Metropolitan Division-leading Penguins doubled their attempts in the third.