Topher Grace Makes His Off-Broadway Debut with Robert DeNiro in the Audience

Topher Grace brought out an impressive crowd Monday when he made his professional stage debut during opening night of Paul Weitz’s comedic Off-Broadway play Lonely, I’m Not at Second Stage’s Tony Kiser Theatre in New York City.

Grace’s The Wedding costar Robert DeNiro came out to see the show, along with Susan Sarandon and Veep actress Anna Chlumsky.

DeNiro didn’t exactly manage to go unnoticed, an onlooker tells PEOPLE. “Robert almost bulldozed an elderly lady on his way into the theatre to avoid photographers,” the source said.