Olympic champion Alina Zagitova second from Anna Shcherbakova with Alexandra Trusova down in fifth after triple Axel fall
Alena Kostornaia eclipsed her own world record to lead a Russian sweep of the ladies' short program at the Grand Prix of Figure Skating Final in Turin.
Olympic champion Alina Zagitova was second ahead of another first-season senior skater Anna Shcherbakova.
Alexandra Trusova finished the day down in fifth after falling on her opening triple Axel.
The four Russians all train together in Moscow under renowned coach Eteri Tutberidze whose latest prodigy, Kamila Valieva, won the Junior Grand Prix Final earlier on Friday.
Talented teenager Kostornaia, one of three finalists making her senior debut this season, was awarded 85.45 after her clean, complete performance opened the competition.
The 15-year-old landed a triple Axel, triple Lutz and triple flip-triple toe loop combination as she beat her previous best of 85.04 set at last month's NHK Trophy.
"[My] coaches set my mind to think the score would be a little smaller, but it was a bit bigger," said Kostornaia. "So it was a pleasant surprise."
Next up was Trusova, best known for her quadruple jumps, which are not permitted in the women's short program.
She took a risk by trying a triple Axel as her opening jump despite having not landed it in competition before.
But the youngster fell, taking a hit to her score and opening the door for her fellow Russians.
Shcherbakova took advantage, skating a season's best of 78.27 to move into second place before a disappointing skate from Japan's defending Grand Prix Final champion Rika Kihira, who put a foot down on her usually solid triple Axel before falling on her combination.
Bradie Tennell delivered a solid skate to move into third, but then it was the turn of Zagitova who skated superbly to post a season's best of 79.60 which leaves her second overnight.
The Olympic champion said afterwards, “I was very nervous today. Finally the adrenalin came and I was waiting for it."
Still only 17, Zagitova explained how her character in the program has developed.
"This [flamenco] character is very close to me. The coaches explained to me how to get into it and, of course, how to interpret it.
"Each movement has a meaning and you can't get it in one practice."
Shcherbakova, who could attempt the quad Lutz and the quad flip in her free skate tomorrow, says she was happy with what she'd been able to bring to the short.
"You can never perform a maximum, you can always do better," she said. "But today I am satisfied with my performance."
Trusova, down in fifth, can make up ground in the free skate where she could attempt five quad jumps. Asked exactly how many after her skate, the 15-year-old said: "You will see tomorrow."
Reigning pairs world champions Sui Wenjing and Han Cong of China won their first Grand Prix Final title but were beaten by compatriots Peng Cheng and Jin Yang in the free skate.
Sui and Han failed to show their formidable top form, scoring 134.19, 13 points down on their season's best, but it was still enough to secure the gold medal with Han struggling on his jumping.
Peng and Jin, meanwhile, skated a season's best 134.60 to take silver overall in a Chinese one-two.
Anastasia Mishina and Aleksandr Galliamov, fourth after the short program, vaulted into the bronze medal spot as fellow Russians Aleksandra Boikova and Dmitrii Kozlovskii faltered in the free.
The French skater slipped during the step sequence in an otherwise solid display of their crowd-pleasing 80s-inspired 'Fame' routine, denying them a runaway victory.
But a score of 83.83 still puts them ahead going into the free dance, with Grand Prix Final holders Madison Hubbell and Zach Donohue going close behind in second with 82.72.
Another American duo, Madison Chock and Evan Bates, complete a tight top three with 81.67, leaving it all to play for on Saturday.