After Mario Lemieux put on a show for Pittsburgh, the Sharks scored the final four goals, dominating the closing moments before improving to 3-1-0 since coach Darryl Sutter was fired. They are 2-1-0 under Ron Wilson.
With the Penguins trying to snap a five-game losing streak, Ricci broke a 2-2 tie with four minutes left, tipping defenseman Bryan Marchment's shot past goaltender Jean-Sebastien Aubin for his eighth goal.
Owen Nolan added his eighth just 54 seconds later and Marleau capped the three-goal burst with 88 seconds remaining.
Lemieux scored a pair of power-play goals to stake Pittsburgh to a 2-1 lead in the second period. He increased his league-leading point total to 53.