The duo scored two goals apiece, and veteran midfielder Giggs hailed the strikers for their hard-work.
"Chicha and Robin were brilliant today and it wasn't only about their goals. Their work-rate and the way they defended from the front and closed players down made it so much easier for the midfielders to put pressure on their players," he told MUTV.
"They'll get the plaudits for their goals, but their work-rate was also important for us."
Van Persie and Hernandez have scored 31 goals between them in all competitions so far this season.