Stiverne (24-1-1, 21 KOs) dropped Arreola twice in the sixth, and the Haitian-born fighter was punishing Arreola again when referee Jack Reiss stopped the fight with 58 seconds left in the round.
The Klitschko brothers had held every major heavyweight title for the past six years. Vitali’s retirement into Ukrainian politics in December opened the WBC belt for the 35-year-old Stiverne, a late bloomer who hasn’t lost in 13 consecutive fights.
After beating Arreola by decision last year, Stiverne hadn’t fought in nearly 13 months while waiting for Klitschko’s decision to retire.
The wait was worth it.
“I studied and studied,” Stiverne said. “I watched my opponent. I knew I could knock him out. ... I was patient. The plan was to let him get comfortable, and he soon as he gets real comfortable, then crack him. And that’s what I did.”