Angela Lee will miss her upcoming atomweight title defence at ONE Championship's Immortal Pursuit card after her involvement in a car accident.

Lee (8-0 record in MMA) was due to defend her belt against Mei Yamaguchi in a rematch in the main event of the Singapore card on 24 November.

However, ONE Championship CEO Chatri Sityodtong posted on Facebook on Wednesday (8 November) that the 21-year-old was involved in a car accident after falling asleep while driving to the gym.

According to the post, police say the car flipped over five to six times with Lee suffering a concussion, minor burns and bruises.

As a result, "Unstoppable" has been withdrawn from the Immortal Pursuit main event with ONE welterweight champion Ben Askren expected to be in the main event to defend his title against Shinya Aoki in what will be his last ever MMA contest.

It serves as a big blow to the Asian promotion as Lee was set to headline the third and final event in what was a historic month for the MMA organisation.

However, she will more importantly make a full recovery and is expected to defend her title for a third time when she is ready to return to action.

It is not yet revealed whether Yamaguchi will receive a short-notice opponent.

Rob DeMello of KHON News in Oahu, Hawaii posted an image on Twitter of Lee's vehicle and the damage that was incurred from the accident.

"If she was not wearing a seatbelt, it would have most certainly been a different story," Sityodtong wrote in the Facebook post. "I saw photos of the damaged car, and it was a complete wreck."

Update: Lee has since given an update on Facebook about the incident, apologising to Yamaguchi and her fans, as well as revealing that she will still be in attendance for the event.