Rockers Metallica delighted fans by playing a secret show in San Diego, California on Friday (19Jul13) as part of the city's Comic-Con festivities.

The group was at the convention to promote new 3D Imax film Metallica Through the Never, and frontman James Hetfield and his bandmates performed some of their classic hits, including Seek and Destroy and Enter Sandman and well as the Star Wars theme and Darth Vader's Imperial March to a sold out crowd of 1,500 people.

Many famous faces joined the audience of fans at the intimate show, including Olivia Munn and her boyfriend Joel Kinnaman, Judas Priest star Rob Halford and Bradley Cooper, who was spotted playing air guitar, reports New York Post.