The actor who played Damien Thorn in the 1970s horror film The Omen punched two cyclists in a road-rage attack and has been given a suspended prison sentence – on Friday the 13th.

Harvey Spencer Stephens, 46, lashed out at two riders and damaged one of their cycling helmets after getting out of his car after a dispute, a court heard. He pleaded guilty to two counts of ABH (actual bodily harm) and one of causing criminal damage following the attack on Toys Hill, Westerham, Kent, on 21 August last year.

Maidstone crown court heard that father-of-two Stephens was “red-faced and angry” when he confronted the cyclists, knocking one of them unconscious after driving up behind them.

Prosecutor Kieran Brand said Stephens repeatedly used his horn when riders Mark Richardson and Alex Manley, who were out cycling separately, were side-by-side on the road as one overtook the other. Richardson responded by flicking his middle finger at Stephens, who then accelerated heavily before overtaking the pair and pulling over.

Brand said Stephens punched Richardson, knocking him unconscious, which prompted Manley to intervene. Stephens responded by asking Manley: “You want some do you?” before punching him twice in the face, causing him to fall on his back with his bicycle still between his legs.

Stephens starred as devil-child Damien Thorn in the Oscar-winning 1976 cult horror film The Omen, alongside Gregory Peck and Lee Remick. Photograph: Ronald Grant Archive

Stephens held Manley down and punched him six or seven times, inflicting dental injuries and damaging his helmet, Brand said.

Brand added: “He described the defendant as being in a complete rage and being out of all proportion to what had happened beforehand.”

Richardson was taken to hospital with swelling to his lip and a broken tooth root, the court was told.

In mitigation, defence counsel Ben Irwin said Stephens, who had no previous convictions, pleaded guilty at the earliest opportunity and accepted he “behaved poorly”.

Referencing his childhood stardom, he said: “As a child he was an actor. That wasn’t a route he wanted to go down and he became a futures trader.”

Judge Martin Joy sentenced Stephens to 12 months in jail, suspended for two years, for the ABH charges and two months’ jail, suspended for two years, for the criminal damage charge.

The judge said: “This was undoubtedly a serious case of road-rage and quite plainly it was a substantial attack, and quite clearly it has had an ongoing effect on the victims.”

Stephens was also made to undergo rehabilitation, 150 hours of unpaid work and told to pay compensation of £1,000 to each victim and an extra £120 to Manley for his damaged helmet.

Stephens sprang to global fame after starring as devil-child Damien Thorn in the Oscar-winning 1976 cult horror film The Omen, alongside Gregory Peck and Lee Remick.

Directed by Richard Donner, the film earned critical acclaim and became one of the highest grossing of 1976, making about £50m at the box office.

In an interview 10 years ago, Stephens said he was chosen for the part aged five ahead of 500 child actors following two interviews. But his film career was short-lived, and after school he went on to work in the City.

He said in 2007: “I was lucky for a few years, nobody saw the film. When it first came out I was left alone, but at about 10 or 11 it then started to come on to terrestrial television, then it started.”

Stephens, of High Street, Edenbridge, said his child fame “went over my head”. “It wasn’t a massive deal. It was good while it lasted,” he added.