Karnel Haughton suffocated on 1st June when his mother Gemma was out of the house buying dinner for the family. She told an inquest into the incident: 'I went to the chip shop and came back in and he was there. I thought he was just messing about. I thought he was just joking'.
Gemma quickly called an ambulance but doctors at Birmingham Heartlands Hospital were unable to save him.
It wasn't the first time that Karnel had played the game, which involves deliberately restricting oxygen to an extreme limit to reach a state of 'europhia'.
'He'd come in at times before and his eyes were bloodshot. He had burst blood vessels on his shoulders,' Gemma said.
'At the time I did not realise where they had come from. But I did research and I guess he had been playing the game before. When he came in with bloodshot eyes I thought it was hayfever or something.'
Karnel is the seventh British schoolchild to fall victim to the craze since 2010 - and in a tragic twist of fate, his school had issued a warning about the game just three months before his death.
Henry French, the former head teacher of Karnel's school, Greenwood Academy, added that the school had taken action after one of their Year 7 pupils was discovering trying the challenge back in March.
'I immediately called an assembly for Year 7 students and I warned students about taking part in this.
'I was very aware not to use anything that could intrigue students. I didn't use the phrase choking game or pass out challenge. I said it could lead to death.
Coroner Emma Brown said that she will be recommending that the Department of Education give guidelines for dealing with the dangerous trend.
'It is clear that Karnel had been trying to experience the sensation of passing out or being close to passing out without realising the consequences of what he was doing and this led to his death,' she explained. 'Any action of trying to become unconscious or short of breath for even the shortest of periods can result in death.'