Her season had started off promisingly enough with her first Grand Prix win at the NHK Trophy in Japan. But a small stress fracture in her foot forced her to pull out of the Grand Prix Finals in December and she has struggled to find her rhythm ever since.

"This year was a little more rough and tumble for me," she said. "I'm used to being at least consistently going up, maybe a little down. Wiping the ice at the Four Continents event and breaking a foot aren't really in my usual plans."

Wagner described her season similarly - too many ups and downs. The veteran skater earned a career-rejuvenating win at the US Nationals, but she was unhappy with other skates at the Grand Prix Finals and in the short program at worlds.

"Today was a huge accomplishment for me," she said. "It might sound silly because I'm 23 years old, but I'm still learning in this sport. I was a late bloomer. To go out there under such immense pressure, to redeem myself in a way, that's something I'm very proud of."

Brown, the 20-year-old newly crowned US champion, was competing in his first worlds. He believes he can build on his experience in Shanghai, as well as last year's Sochi Olympics, to get ready for the next worlds, which are on home soil in Boston in 2016.

"I couldn't be more excited. I am fourth in the world," he said. "I did everything perfectly and I'll take what I learned from there."

For the other Americans, Polina Edmunds finished eighth in the women's event, and Adam Rippon was eighth and Joshua Farris 11th in the men's.