Benedict Cumberbatch came to the aid of a food delivery man on a bicycle as he was being attacked by four assailants in London.
Witnesses said Cumberbatch yelled, "Leave him alone!" at the attackers, then jumped out of his car and dragged the men off of the victim when they wouldn't stop.
The attackers fled the scene with nothing and Cumberbatch hugged the victim, making sure he was OK.
"Benedict was courageous, brave and selfless," said Manuel Dias, the Uber driver who also tried to help.
"Here was Sherlock Holmes fighting off four attackers just round the corner from Baker Street."Baker Street is the fictional home of the detective Cumberbatch plays on the television series "Sherlock."
The Sun said Cumberatch played down his involvement in the incident.
"We'd like to thank Benedict Cumberbatch for his heroic actions. On behalf of everyone at deliveroo: thank you so much," a spokesman for the victim's employer, Deliveroo, said.