Rod Stewart's son has pleaded not guilty to charges stemming from an alleged assault on a couple outside a party in the Hollywood Hills.

Sean Stewart, 27, entered his plea Thursday in Los Angeles Superior Court.

He faces two counts of assault with a deadly weapon and one count each of throwing a substance at a vehicle and vandalism with more than $400 damage.

"We vigorously dispute the allegations," said Stewart's defense attorney, Dana Cole. "We believe Sean was misidentified by the complaining witnesses in the case."

Stewart arrived at court 25 minutes late and was warned to be on time for his next hearing.

"People have to come to court on time," Superior Court Judge Stephen A. Marcus told him. "I'm not waiting for defendants."

The couple, Tobalus and Ericka Stein, claim Stewart and others riding in a Rolls-Royce Phantom confronted them, then began punching and throwing bricks at them and their vehicle outside the April 22 party.

Stewart, one of the stars of the A&E cable show "Sons of Hollywood," was arrested in June.