After a day of testimony — which included evidence from his teenage accuser — a martial arts coach pleaded guilty to one of the charges he faced, bringing his sexual assault trial to an abrupt end.

Tyrone Hill, of Whitby, faces sentencing early next year after pleading guilty Thursday to one count of invitation to sexual touching. He also faced charges of sexual assault and sexual interference, but prosecution of those counts has ended with the guilty plea.

The sudden about-face — Hill had pleaded not guilty to all three charges during an arraignment in Superior Court on Monday — came after jurors heard from the teenage girl he was alleged to have assaulted.

In a statement to Durham police in 2017 the girl acknowledged a relationship with Hill that began when she was 14 and he was in his mid-20s. The two met when the girl signed up for martial arts classes, court heard.

In the video, which was played for jurors Wednesday, the girl said she had engaged in intercourse with Hill once, in late 2016. The soft-spoken teen — sometimes her voice was barely audible as she appeared to respond reluctantly to a detective’s questions — said Hill was aware of her age, and had warned her that he’d wind up in trouble if anyone found out about the relationship.

“I didn’t want him to get in trouble. He said he was going to lose his life — everything he’d worked for,” the girl said. “I was in love with him.”

In earlier testimony the girl’s mother said she grew suspicious of Hill soon after the girl enrolled in martial arts, and that she’d warned him about “inappropriate” behaviour with her. She said her suspicion only deepened when she checked her daughter’s phone and found a picture of Hill kissing the girl.

Police became involved after a number of students approached the principal at the girl’s school with concerns about the relationship, court heard.

Hill returns to court for sentencing Feb. 3.