Jamie Langenbrunner erased a 1-0 St. Louis deficit with a marker 11:16 into the final frame, then Perron followed only 45 seconds later with another tally, boosting the Blues into the lead.
Andy McDonald added an empty-netter to ice the victory and the Blues defeated the Sharks 3-games-to-1 in their Western Conference quarterfinal series, advancing to the second round of the NHL playoffs for the first time since 2002.
Brian Elliott turned aside 26-of-27 shots to earn the victory.
Susan Sarandon 'very excited' about daughter's pregnancy
Dennis Rodman pledges to end trips to North Korea