Connor Harrison, 10, is the youngest person in Britain and the second youngest person in the world to have the procedure, which involves the surgeon speaking to the patient so they can ensure the surgery is not affecting their speech.
Connor's mum Sarah Warren, 29, said: "They said it was next to the speech part of the brain and they needed to operate. The family were told Connor would be woken during surgery to test his speech was not being affected. When they had opened him up they slowly started to wake him. They used a stimulator touching part of his brain to test it."
The worried mum admitted she had been concerned about how Conner would cope with the operation, but he dealt with it all so well his doctors gave him a bravery medal when he came round!
A spokesman told reporters: "By speaking to a patient the surgeon can be precise in dealing with a tumour in a speech area. It is rare for children because we need to be confident they can cope mentally with being woken during an operation."
Connor underwent the six-hour procedure at Leeds General Infirmary on July 1. The little boy has previously beaten leukaemia and had a bone marrow transplant. He will now have radiotherapy and chemotherapy as the brain tumour was so aggressive.
His grandmother Jackie McEvoy said brave Connor was not worried about more treatment, saying : "When he found out he had to have radiotherapy and chemo he said, 'I'm not worried. It's a doddle.'"
What a brave boy.