Swimming star Rikako Ikee, who is recovering from leukemia, claimed a Tokyo Olympic berth in the women's 4x100 freestyle relay on Thursday after winning the 100-meter freestyle at Japan's national championships.

Ikee won in 53.98 seconds and has now qualified for two Olympic events. Her 100 butterfly victory on Sunday at Tokyo Aquatics Centre earned her a place on Japan's 4x100 medley relay team.

Ikee missed out on spot in the women's 100 freestyle, which required her to finish first or second and beat 53.31, as required by the Japan Swimming Federation. Relay qualification required a 54.42 time, a top-four finish and a combined time of the top four swimmers better than 3:37.68.

"I'm happy to have come below 54 seconds, but I wanted a little faster time, honestly speaking," Ikee said.

"This event was all about getting in the top four and bettering the required standard. I had a good race and was determined to come below 54 seconds so I'm glad to have got that time."

Natsumi Sakai, Chihiro Igarashi and Rika Omoto joined Ikee in qualifying for the 4x100 relay team.