Deontay Wilder has retained his WBC world heavyweight title thanks to a fifth-round stoppage of Gerald Washington in his home state of Alabama.
The 31-year-old, contesting his first fight since breaking his right hand in his July victory over Chris Arreola, showed some rustiness on Saturday in Birmingham.
He laboured through the first four rounds but stepped up his game in the fifth, dropping his fellow American challenger with a short right hand then following with a flurry of fight-ending hooks.
Wilder, who won the WBC title in 2015 with a unanimous 12-round decision over Canada's Bermane Stiverne, now has a 38-0 win record, 37 of which have come by knockout.
For Washington - who had stepped into the fight after Wilder's planned opponent, Poland's Andrzej Wawrzyk, tested positive for a banned substance - it was a first defeat in 19 bouts.