A California dad has been granted full custody of his now four-year-old son after the boy's mother tried to raise him non-binary and forced him to wear dresses and make up.

Harrison Tinsley announced his victory in the years-long legal battle with his ex-girlfriend to gain full custody of his son, Sawyer, in an update on his online fundraiser for legal fees on July 18.

The father-of-one described how he felt like he was 'watching a miracle' when he found out he would be the boy's full-time caregiver.

'It definitely is a pretty wonderful feeling to fight for something so hard and to actually achieve it,' Tinsley told The Daily Signal. 

Tinsley explained that he had always wanted to be a father and was 'ecstatic' when his girlfriend told him in 2019 she was pregnant.

'Unfortunately that excitement turned to pain when his mother, who suffers from serious underlying mental health problems, abruptly ended our relationship and prevented me from seeing Sawyer,' he wrote in the fundraiser.

Tinsley was only able to meet his son when Sawyer was 15 months old, and the two quickly bonded.

'Sawyer is not only my best friend, he is the most amazing, greatest blessing of my life,' he said.

But the boy's mother had begun a same-sex relationship and started to identify as non-binary - treating Sawyer as non-binary as well.

'She calls him "they" and puts him in dresses, girl diapers and makeup,' Tinsley wrote.

'She threw Sawyer a girly-themed party for his second birthday party where she made him wear a dress donned with a sheriff's badge.'

At another time, he told The Daily Signal, the mother brought Sawyer to Disneyland - but would not let him go on the rides unless he wore the princess shoes she got him.