Russians claimed the top two places in the women's figure skating short program on Tuesday, but Japan's Kaori Sakamoto put herself into contention with a wonderful performance that secured third.
Sakamoto scored 79.84 points, while her countrywoman Wakaba Higuchi also kept the Russian Olympic Committee athletes honest with a skate that was awarded 73.51, good enough for fifth.
Kamila Valieva of the Russian Olympic Committee shook off the doping controversy that has engulfed her to score 82.16 and take the lead. Her teammate, Anna Shcherbakova, received 80.20 and is second.
The other Russian, Alexandra Trusova, was knocked off the provisional podium by Sakamoto but remains a medal threat with her 74.60.
Sakamoto opened with a double axel and then ramped up with three triples, including a flip-toe loop combination.
Her element score was higher than Shcherbakova's but the Russian had the edge in presentation.
"I've never come that close to 80 points in international competition. To be able to get a score like this without a triple axel was a great experience and something to build on," said Sakamoto, 21, whose previous personal short program best was 77.78.
"I was so nervous before I started that I was on the verge of tears, and I couldn't stop thinking about how I'd do. But somehow I was able to string together my jumps."
"Today confirms the work I've put in during practice."
Higuchi had three flawlessly performed triples, an axel, a lutz-toe loop combination and a flip but did not approach her personal best in the segment of 79.73 set in late 2021.
The 21-year-old, who was the 2018 world championships runner-up, combined her jumps with an expressive performance.
"My goal was to nail a triple axel, and I'm glad I pushed myself to do that. My score, however, was not good, and my frustrations outweigh (my success with) the axel."
Valieva, whose buildup to the women's event has been marred by an eligibility controversy linked to the results of a December doping test that showed she had a banned substance in her system, was given a vocal welcome as she entered the rink.
The 15-year-old Russian stepped out of her triple axel landing, but otherwise hit her marks on three other triples.
Early in the evening's skating, Japan's Mana Kawabe earned a place in the free skate with a 62.69 score.
She fell in a tangle of legs on her first jump, a triple axel, but completed her skate with a fine triple lutz-triple toe loop combination and a triple flip.
Kawabe, who at 17 has already had a Grand Prix podium this season when she finished second at the NHK Trophy with personal best short and total scores, held the provisional highest score for a period before sliding down to 15th.
"My axel was pretty good but I was distracted by the other skaters in the 6-minute warmup so I couldn't concentrate on my own practice that much, and that led to mistakes.
"Now, I want to build momentum and go forward without being scared to make a mistake."
The women's free skate will be on Thursday.