Valieva led home fellow 14-year-olds Maiia Khromykh and Daria Usacheva with Elizaveta Tuktamysheva fourth to boost World Champs hopes and Alena Kostornaia only sixth.
The next generation of Russian women dominated the domestic figure skating Russian Cup Final with Kamila Valieva coming out on top in Moscow on Sunday (28 February).
Leading the field by almost 10 points after Saturday's short program in the ladies' singles, the world junior champion needed all of that advantage as she fell twice and under-rotated a jump in her skate to Ravel's Bolero.
Valieva was only third in the free skate with 149.29, but that gave her a winning total of 238.00.
Maiia Khromykh, another member of Eteri Tutberidze's Sambo-70 unit, landed two quads to take free skate honours and second place overall with 235.96.
Their training partner Daria Usacheva was second in the free skate to round out the podium with a total of 229.71.
All three are too young to compete in next month's World Championships in Stockholm, with Elizaveta Tuktamysheva boosting her hopes of making the Russian Figure Skating Federation team by taking fourth place.
Still seemingly feeling the after-effects of Covid-19, which ruled her out of December's nationals, Alena Kostornaia ran out of stamina in her free skate and was unable to improve on her sixth place from overnight.
Having previously said she would retire after Beijing 2022, Kostornaia - who was in tears after her short program - said that recent events had prompted a rethink.
She told Sport24, "Of course, it will be a shame not to go to the World Championships. But this is how it is in sport. It's not the end of the world.
"Even though I said that I would finish after the Olympic year, now I think, 'Why not skate on?' I cannot imagine my life without figure skating. I will skate for as long as my health permits it."
Lying in sixth place, Kostornaia was the first skater to go in the final group.
It was a solid free skate from last year's outstanding female skater who left Tutberidze to work under Evgeni Plushenko in the close-season.
But she looked fatigued in the closing stages and under-rotated her last jump, a triple Lutz, while the triple Axel which helped her to last season's Grand Prix Final and European titles was absent.
Kostornaia's trademark elegance was largely there, but she remains some way short of her stellar best.
She scored 140.06 to finish with a total of 210.20, only good enough for sixth place behind another youngster, Anna Frolova.
And the improvement 17-year-old Kostornaia will need to make to return to the summit was clearly illustrated moments later by one of her former training partners as Maiia Khromykh opened her free skate with a stunning quad toe loop and quad Salchow.
The 14-year-old - who was fourth at last year's world juniors, had the performance of her life in the Megasport Arena, opening her free skate with a quad toe loop and a quad Salchow.
The confidence grew from there with the falls which had bedevilled her in the past nowhere to be seen.
Khromykh scored 162.16 - over 20 points clear of Kostornaia - to set the target of 235.96.
Tuktamysheva started her free skate off in superb style with a triple Axel-double toe loop combination although she had to take a step on her subsequent triple Axel.
But this was a much more vibrant display from the 2015 world champion who had been below-par at both the Russian nationals and Channel One Cup after contracting Covid-19 following her victory at the Rostelecom Cup.
A hand down on a spin near the end of her routine left her down on what she could have achieved, but Tuktamysheva had more than enough to overtake Kostornaia with this competition billed as a shoot-out to join Anna Shcherbakova and Alexandra Trusova on the flight to Stockholm.
A veteran in figure skating terms at 24, 'The Empress' scored 148.27 for a total of 226.01 and fourth place.
Afterwards she told Sport24 that she will "just enjoy" being at the Worlds having not been there for so long.
Usacheva may lack the jumping pyrotechnics of some of her Sambo-70 colleagues, but she produced another excellent and stylish skate to move above Tuktamysheva into a guaranteed podium finish.
That left just Valieva to go, and the third of Tutberidze's 14-year-old prodigies suffered an early setback as she under-rotated and fell on a quad Salchow.
Her jumping was not up to her usual high standard, and she fell again on a quad toe loop with that overnight advantage looking in serious peril.
In the end, the judges decided she had done just enough to take overall victory with the result bolstering her credentials as a prime contender for gold at next year's Winter Olympic Games.
Russia's new figure skating sensation said, "I worked so hard for a long time to do two quads in a free program. Everything bore fruit. I left everything on the ice.
"I have a great desire to get into the Olympic team, and then fight for the podium."
Just as the '3A' of Kostornaia, Trusova and Shcherbakova, swept all before them after excelling in junior competitions, Valieva, Khromykh and Usacheva all ascend to the senior ranks next season and can already be considered among the medal favourites at Beijing 2022.
Earlier, Russian junior champ Evgeni Semenenko won the men's singles with Anastasia Mishina and Aleksandr Galliamov completing victory in the pairs event.