A Muslim "bully" grabbed a schoolboy by the throat and threw him to the ground because he saw him hugging a girl in the street, a court was told.
Michael Coe, 35, was driving through east London when he spotted the two 16-year-olds cuddling on the pavement.
He allegedly confronted the pair, demanding to know if they were Muslims, before calling the girl a "whore".
Coe was said to have grabbed the boy by the throat, causing him to black out, before he woke up bleeding on the floor.
When passing schoolteacher Boutho Siwela tried to come to the couple's aid, Coe then allegedly attacked him.
Coe is on trial at Southwark Crown Court accused of assault occasioning actual bodily harm and battery.
Prosecutor Jonathan Polnay described the attack as "completely unjustifiable".
He told the jury: "This case is about what started as unpleasant bullying with religious overtones in the street, followed by an attack by this 35-year-old man on a 16-year-old schoolboy.
"This was followed by a further assault on a schoolteacher, a nearby bystander, who came to his aid when he saw what was going on.
"The victim was, and is, a schoolboy and, in the early evening, he was there with his girlfriend standing on the pavement in the street, cuddling each other in the street.
"They had the misfortune that, of all the people to drive by, it was this defendant who was driving by in a car."
Coe demanded to know if the teenagers were Muslim and when they lied and said that they were not, he replied: "Why am I wasting my time with you if you're not Muslim?"
He then called the girl "a whore" before attacking her boyfriend, Mr Polnay said.
"He (Coe) grabbed him around the neck, that's the last thing the victim remembered," he added.
"The next thing the boy woke up on the floor and he was bleeding.
"This was completely unpleasant and utterly unwarranted - this is a grown man on a child."
Mr Siwela heard the girl screaming and took a photo of Coe's number plate as he was getting back into his car.
Mr Polnay continued: "The defendant wasn't having that and he comes over to Mr Siwela and said give me that phone.
"Mr Siwela didn't want to hand over his phone so the defendant grabbed him and threw him to the floor. He then got in the car and drove away."
Coe denies the two charges against him. He admits assaulting the 16-year-old boy in Wilson Road, Newham, on April 15 but claims he was acting in self-defence.
The trial continues.
The victim, who cannot be named because he is under 18, said he was hugging his girlfriend goodbye when Coe shouted "let that little schoolgirl go".
He later demanded: "Why are you acting like a punk in front of your whore girlfriend?" before attacking the boy.
"Within seconds of saying that I felt a hand on my neck and after that I don't remember anything else," the teenager said.
"I woke up - there was blood on my hands and I could feel blood on my face, my head was throbbing and I was very dizzy and also felt sick."