Uta Abe suffered her first defeat in almost exactly three years, going down to Amandine Buchard in the 52kg final of the Osaka Grand Slam on Friday.
The 19-year-old Japanese sensation, who retained her judo world title in Tokyo in August, was beaten by a modified kata-guruma (an over-shoulder throw) scoring waza-ari after four minutes of golden time.
Abe could scarcely believe it, and was unable to stem the flow of tears at the victory ceremony some 10 minutes later.
It was an important defeat as the All Japan Judo Federation had announced that current world champions who took victory at the final Grand Slam of 2019, in their home country, would be selected for the Tokyo 2020 Olympic Games, subject to final approval from the country's High Performance Committee.
Reigning world 66kg men's champion Joshiro Maruyama suffered a similar fate, losing to Abe's older brother Hifumi - a two-time world champion himself - also in extra time.
Contrasting family fortunes
For Hifumi Abe, it was do or die for his Olympic hopes.
The 66kg world champion in 2017 and 2018 went down to Maruyama in this year's semi-finals in Tokyo with his compatriot taking the crown.
Victory for Maruyama in Osaka would have seen him take the sole berth for Tokyo 2020.
But Abe showed he meant business with two scores against Yuji Aida to set up the final everyone had been waiting for.
The final was a tight and tense affair with neither man able to score in regulation time.
Just under a minute into the golden score period, Abe had a good grip on Maruyama's belt but could not lift him to complete the job.
He was definitely in the ascendancy though and, after 3:27 of extra time, he countered an off-balance Maruyama and put him on the deck for a waza-ari score to level their head-to-head series at 2-2.
The pair will almost certainly have to meet again to decide who takes that coveted spot at a home Olympics.
Aida and Yuki Nishiyama took the bronze medals with respective wins over Spanish pair Daniel Perez Roman and David Garcia Torne.
Minutes later, it was the turn of Uta Abe, who faced 2018 world bronze medallist Amandine Buchard.
The Frenchwoman was on the defensive for much of normal time, resisting the teenage prodigy's potent uchi mata (inner thigh throw) to force golden score time.
Buchard then showed more attacking intent with Abe unusually on the back foot.
And it was the underdog who stunned the home crowd into silence, just managing to thrust her opponent over her shoulder for the decisive score and her first win in five encounters.
As Buchard roared with delight, Abe appeared to be in a state of shock after her first defeat since going down to Natsumi Tsunoda at the Tokyo Grand Slam in December 2016.
With 2017 world champion Ai Shishime and this year's Budapest Grand Prix winner Chishima Maeda taking bronze medals, Abe now has more work to do to book her place at Tokyo 2020.
Buchard was the only overseas judoka to take gold on the opening day in Osaka with Japan winning four of the five titles on offer.
Olympic bronze medallist and three-time world champion Naohisa Takato defeated world number one Ryuju Nagayama in the final of the men's 60kg class.
Takato lost out Nagayama in the bronze medal bout at this year's World Championships, but avenged that defeat with an ashi-waza leg throw against the run of play in golden score to notch up a record 10th Grand Slam title.
The win also boosts his hopes of making Tokyo 2020.
Funa Tonaki closed in on a Tokyo berth with her fourth Grand Slam title at 48kg.
The 2017 world champion has been beaten by Ukrainian teenager Daria Bilodid in the last two world finals, but showed she is the best of the Japanese with a hard-fought win over another former world champ, Rio 2016 bronze medallist Ami Kondo, in the semi-finals.
Tonaki then defeated Spain's Julia Figueroa, scoring first with an osaekomi hold and then again with a counter to win by ippon with 14 seconds to go.
Momo Tamaoki scored her first Grand Slam success by beating Chinese Taipei's Lien Chen-Ling in the women's 57kg final.
Tamaoki followed up a waza-ari score with an upper hold for 10 seconds for victory by ippon.
The 25-year-old, who won at last year's Asian Games title and mixed team gold at the last two World Championships, surprised 2018 world champion and 2019 world silver medallist Tsukasa Yoshida in the semi-finals in golden score.
Japan will be expecting plenty more success over the next two days and reigning +78kg world champion Akira Sone can book her place at Tokyo 2020 by taking victory on Sunday.
Hoping to spoil the home party is Brazil's two-time world champion and Pan American Games holder Mayra Aguiar.
The 28-year-old claimed bronze at London 2012 and on home soil at Rio 2016 before collecting another bronze at this year's World Championships in Tokyo.
Aguiar always enjoys competing in Japan, and will hope to make an impression ahead of her bid for a third Olympic medal.