Ashley Wagner celebrates following her free skate during the Ladies competition at the ISU World Figure Skating Championships in Boston on Saturday. (Geoff Robins/AFP/Getty Images)

BOSTON — There had already been four clean performances, one world-record-setting, before American Ashley Wagner stepped onto the ice. Gracie Gold, the leader going into Saturday’s world figure skating championship final, had wilted, and the crowd was tense. Wagner, the least technically proficient of the final group, held on to every jump. She skated with speed and ferocity, channeling the emotions of the cabaret singer Satine from “Moulin Rouge.”

By the time she struck her landing pose, the result was clear. Wagner, ever the underdog, wound up in second place and became the first American woman in a decade to win a medal at the world championships. The drought was over.

“This is a big deal,” she gushed. “I’m excited!”

In the end, Wagner’s maturity — the steadiness of how the 24-year-old glides on the edges of her blades, her posture and her lightness in the air — was the key to success. It was evident from the first 30 seconds of her skate.

Those qualities are measured in the judges “components mark,” which measure things like transitions, skating skills and choreography. They padded Wagner’s technical weakness after she received deductions for landing two triple jumps without fully rotating them in the air. You can tell, in the most basic terms, by how much she twists her landing foot when she returns to the ice.

Even on her best day, Wagner would not be able to catch the program of Russia’s Evgenia Medvedeva, effervescent in a four-minute long program that judges deemed the best since the sport changed its judging system. Medvedeva, 16, is the latest in a line of successful Russians, but she stands out because of her incredibly precise jumping technique. That quality could allow her to last longer than the previous young Russian wunderkinds, who struggled after their bodies changed and could no longer launch into the air so easily.

Medvedeva was in third place going into the long program, after being stiff in the first phase of competition. Her coach, Eteri Tutberidze, said she told her: “Don’t rush and do everything you can. Skate. Breathe. Jump.” And out came a more confident, fluid skater. Medvedeva started the program looking confused, searching for something special. But it was all an act. She quickly pushed out her chest and powerfully pivoted from one side of the rink to another, an enchantment with each edge. Her jumps were high in the air and had steady landings. She was also the only skater to perform two sets of triple jump-triple jump combinations. Untouchable.

The one skater who could have beat her that night was Gold, who skated to Igor Stravinsky’s “Firebird,” the ballet of resurgence and triumph. But the long program ended up being more of the same in Gold’s skating history: brilliant and botched.  First, Gold messed up her trademark jumping pass — the difficult triple lutz followed by a triple toe loop — after landing a little too much on her heel and taking a stumble. Later, she did not have enough speed for the spring into her second triple lutz — which takes off when the skater vaults into the ice using the side of the blade outside the leg — and doubled that jump. She ended up in a respectable fourth place, behind Russia’s Anna Pogorilaya.

Gracie Gold, during Saturday’s free skate. (Maddie Meyer/Getty Images)

The breakdown was reminiscent of Nancy Kerrigan’s breakdown at the world championships in 1993 and yet also vintage Gold, who has struggled with nervousness all her career.

With the best chance of her career, Gold’s medal dreams were dashed. And she found herself questioning whether she could be a world champion — ever.

“I feel really ashamed of how I skated and I want to apologize to my country and to the crowd here — there’s no excuse for it,” Gold said to reporters, later adding: “It shows that I’m not up there with the rest of the world.”

Keeping up with the world will get no easier. Gold must master her nerves if she is ever to be a champion, but she must also start completing more difficult jumping passes — as does Wagner — before heading into the 2018 Olympics. Medvedeva and the other Russian skaters plan to incorporate even more difficult jumps, including quadruple jumps and the treacherous triple axel, to pull ever farther ahead of America’s stylists.

Wagner’s moment was well-deserved and nothing can take that away. But as the singer bellows at the end of her “Moulin Rouge” program, “The Show Must Go On.” And for the American women, their game must step up.

More figure skating:

Men’s final: The swag of the Spainard soars over shaky field

For Americans at worlds, it might be all about the dance

The best African American skater in history is now bankrupt, living in trailer