Ali had predicted she would knock out Pennybaker, a 28-year-old accounting student from Pittsburgh who was making her professional debut, but was unable to land any solid blows early.
Early in the fourth round, Ali bloodied her opponent's lip, forcing a standing eight count, and then sent Pennybaker reeling into the corner, after which the referee stopped the fight, a move which upset Pennybaker's corner.
By going nearly the full scheduled distance, the bout was a more complete test than Ali's debut. Just over a month ago, on 8 October in Verona, New York, she needed just 31 seconds to knock out April Fowler.
Ali's father, who watched her first fight from the ringside, did not attend the second, but Veronica Anderson, Laila's mother and Ali's third wife, watched the fight from ringside.
The bout was the fifth of a seven-fight card at the resort.Reuse content