Football coach Barry Bennell pinned a schoolboy to a wall in Crewe Alexandra's changing rooms with a "Darth Vader grip" after he interrupted him fondling another youngster, a jury has heard.
The witness told Bennell's sex abuse trial that the defendant then threatened he would ruin his football career if he told anyone what he had seen at the club's Gresty Road ground.
Liverpool Crown Court heard that the witness gave his account of the alleged incident in the 1980s to police after reading press reports about Bennell in 2016.
Giving evidence on Tuesday, the then Crewe youth team player recalled that he rushed back to Gresty Road from the nearby railway station after he realised he was missing one of his football boots.
As he entered the changing room, he said, he saw a young boy half-dressed and sitting on Bennell's knee, he told the court.
The witness said Bennell's left arm was around the youngster in a "cuddling fashion" and that Bennell was fondling him down his football shorts.
He said: "Obviously, Barry was startled to see me come back. He got up and shouted at me and said 'What the f*** are you doing?' and I said 'I have come for me (sic) boots and what are you f****** doing?'.
"At that point he jumped up, stormed at me and pinned me to the wall. If you can imagine Star Wars and Darth Vader, it was like a Darth Vader grip."
He said the young boy ran out of the changing room and Bennell then told him: "You have not seen anything. If you say anything to anyone I will make sure I will finish your football career here and now."
The witness said that from then on Bennell had a "psychological hold" over him.
He said: "I was upset. I didn't really want to talk to anyone about it. I was still in total shock at the time."
The court heard that the witness contacted police after reading press reports about Bennell in 2016 because he knew other boys he used to play with had been involved with the defendant when he coached at Manchester City.
Eleanor Laws QC, defending, said to the witness: "I am going to suggest you are not telling the truth about this incident at all."
The witness replied: "That is your opinion. I know it happened."
Miss Laws asked him why he had not told a friend, who was catching a train with him at the time, if he was "that worked up about it".
He replied: "I was threatened, if I breathed another word of what I had seen, I would never play football again. All I ever wanted to be was a professional footballer."
The young boy the witness claimed Bennell had fondled is one of 11 complainants aged from eight to 14 who say they were abused by Bennell, 64, between 1979 and 1990.
Bennell denies offences of indecent assault, buggery and attempted buggery.