China's He Bingjiao on Sunday booked a place in the women's badminton singles final at the Paris Olympics after her semi-final opponent withdrew because of injury.

Spain's Carolina Marin, who won gold in the 2016 Rio Games, started off strong against the Chinese shuttler, taking the first game 21-14.

Marin was leading 10-6 in the second when she appeared to have injured her right knee and collapsed to the floor in tears.

She put on a knee brace and played two more points before deciding to retire.

The Spaniard limped off the court to a standing ovation from the crowd.

Her Chinese opponent told reporters that she felt very sad about what had happened.

"She was playing perfectly well and I was very passive," said He. "I wasn't thinking about the final at all."

He advanced to the final to play world number one, An Seyoung from South Korea, who beat Indonesia's Gregoria Mariska Tunjung in the other semis. (Additional reporting by AFP)