Kazakhstan’s Elizabet Tursynbaeva was second, while fellow Russian Evgenia Medvedeva claimed the bronze.
Olympic Champion Alina Zagitova can add World title to her resume.
Her win at the ISU World Figure Skating Championships in Saitama, Japan, is her first major victory since gold at the Pyeongchang Games 13 months ago.
Kazakhstan’s Elizabet Tursynbaeva was second, while Evgenia Medvedeva of Russia claimed the bronze.
Zagitova is the first female skater since Katarina Witt in 1984 to win the Olympic title before the World championship.
The 16-year-old Russian burst onto the scene in January 2018, taking the European title just weeks before becoming Olympic champion.
What followed was a fifth place finish at the 2018 World Championships after suffering three falls in the long program. This year, she missed the top step of the podium at both the Grand Prix Final and the European Championships, settling for silver in each.
After a dominating, season-best short program, Zagitova said her coaches’ patience with the ups and downs of her season – including a fifth-place finish at the Russian Championships – helped make her stronger.
"During this season, I actually experienced many mistakes during practice and that made me more nervous," Zagitova told media at her post-competition press conference after her Short Program. "But thanks to tremendous support from my coaches, I was able to overcome those mistakes and errors and really get prepared mentally which was what I needed to do for this competition."
That mental preparation continued to pay dividends Friday evening. Though she appeared to tighten up slightly toward the end of the program, she landed seven triple jumps on her way to a 155.42 score. Her overall score was 237.50.
"I'm very happy," Zagitova said in the post-event press conference. "I tend to forget both my victories and my failures. I simply set a goal for myself in the season and then start my journey towards that goal."
Rika Kihira, Kaori Sakamoto and Satoko Miyahara, all of Japan, claimed fourth, fifth and sixth, respectively, in front of a boisterous home crowd.
A disciple of Russian coach Eteri Tutbertidze, whose pupils have come to dominate the junior and senior levels of ladies skating, Turnsynbaeva trains alongside Zagitova. Tutbertidze’s skaters are known for their incredible jumping ability, often times firing off strings of triple jumps in practice.
That jumping ability was on full display Friday, as she became the first senior woman to land a clean, fully-rotated quadruple jump in competition. Russia’s Alexandra Trusova and Anna Shcherbakova, juniors, have previously landed quads.
Tursnybaeva has attempted the jump in competition before, including the recent Four Continents where it was called for an under-rotation.
It was a quadruple Salchow, her opening jump, that made history.
"I can't believe I landed it," Tursynbaeva said afterward.
"It was pretty good in the practice today in the morning, but I couldn't get it in the program for the past two competitions. When I stepped on the ice, I just felt great, like 'I can do it', and it just happened."
The feat lifted Tursynbaeva to her first World medal with a 224.76 total score. Her previous best finish at the Worlds was ninth.
In addition to her historic quadruple jump, she also became the first woman to win a figure skating medal at the Worlds for Kazakhstan.
I'm really happy with my silver medal. It was unexpected for me, the first (women's) medal for Kazakhstan," Tursynbaeva said. "I tried not to think about anything when I was competing, and just focus on my program."
The 19-year-old Medvedeva returns to the podium after taking the title back-to-back in 2016 and 2017. She skipped last year's Worlds.
After two years undefeated, Medvedeva came runner-up to teammate Zagitova at the 2018 European Championships and Olympic Games. The Russian star then sought the help of famed coach Brian Orser to re-invent herself.
The progress has been slow at times, including at the Russian Championships when a disappointing short program dropped her to 14th place going into the free program.
Friday night, she was all business in all black. Her laser like-focus carried her through seven clean triple jumps. The only flaw came toward the end as her final double Axel received an under-rotation call.
Her performance marks a return to form and she could not contain her joy. After hitting her final position, she fist pumped the air while Orser and fellow coach Tracy Wilson beamed from the behind the barrier.
"It was really the first time for me that I’m doing free program every day and some times a few free programs in a day," Medvedeva said of her preparation before coming to Saitama. "So for me, that was like 200% work than I usually do, and I was totally ready for this end."
As her season’s best score, a 149.57 in the free and 223.80 overall, was announced, Medvedeva covered her face in shock to the delight of the crowd.
"I'm so satisfied with all my performances," she said. "I'm proud of myself, but I'll only be happy for a few days. Then, I'll calm down and be ready to work more."
Kihira has become known for her ability to rally after a disappointing Short Program. After missed elements in the short program at both the Grand Prix Final and Four Continents Championships earlier this season, Kihira skated lights out to take the gold medal at each.
She entered Friday's competition in seventh place. A comeback here would have been the third major title where she’d sealed a come-from-behind victory.
At the start, it looked like lightning might strike a third time as she opened with a stunning triple Axel, triple toe combination. But then, she came to grief on her second triple Axel attempt moments later.
She recovered strongly and landed an impressive seven triple jumps to score 152.59 in the free skate and 223.49 overall. She finished less than half a point back of Medvedeva.
“I think it was a really great season,” she said afterward in the mixed zone. “This wasn’t the kind of performance that I would be satisfied with anyway but I don’t want to rest on my laurels, (I want to) train hard and stay injury free and aim higher.”