The victory by the Japanese skater, who also won at the 2007 Worlds, was fitting in a competition that was originally scheduled in her homeland before it was hit by an earthquake and tsunami in March.

“I was skating for Japan and I never cared about the result,’’ said Ando. “I’m really happy to have a gold medal. I worked hard and I’ve become a little bit of a stronger skater than a year ago.’’

For the United States, Alissa Czisny finished fifth in the free skate and overall standings. American Rachael Flatt was 12th overall.

In ice dance, Americans Meryl Davis and Charlie White won the first world gold for their country in the discipline, outpointing 2010 champions Tessa Virtue and Scott Moir of Canada. The American sister-brother team of Maia and Alex Shibutani won bronze.

The free programs of Ando and Kim contained languid moves interspersed with moments of power and steely control. They were within less than a half-point of each other going into the free skate.

Ando, skating to Grieg’s “Piano Concerto in A Minor,’’ in the final group of six, opened with a triple lutz-double toe loop. She didn’t falter until the middle of the program, when she stepped out of a double axel and reduced the planned combination triple toe to a double.

But she regained her poise, had three more solid triples and a double axel-double loop-double loop cascade so surprising that it drew gasps from the crowd.

Kim made her season debut after firing coach Brian Orser and moving her training base from Toronto to Los Angeles in the past year. She started even more boldly with a triple lutz-triple toe. Her program — “Homage to Korea’’ — set to a haunting collection of traditional Korean music and choreographed by Canadian David Wilson, was a crowd-pleaser.

But she quickly ran into trouble, singling two of her next three jumps. She also featured a cascade starting with a double axel, but one of the jumps was a toe loop instead of a loop, giving the element slightly less value.

“I’m just so glad that the competition is over,’’ said Kim, who cried on the podium. “After the Olympics, I was thinking: ‘Am I going to come back to competition or not?’ I couldn’t stop thinking: ‘Why do I have to do this?’ I think that was the hardest thing. But then I felt ready to go and I thought: ‘I can do this.’ ’’

Carolina Kostner of Italy improved from sixth place to take the bronze, with a charming program to the dreamy strains of Debussy’s “Afternoon of a Faun,’’ marred only by popping one triple.

“Last year it was a hard time for me, so it was a big emotion just to finally again just enjoy it,’’ she said. “To be able to get a medal just makes it more special.’’

The American ice dancers thanked their coaches, Igor Shpilband and Marina Zueva.

“To say that we owe everything to our coaching is an understatement,’’ Davis said.

Davis and White were slightly behind going into the free dance, but outpointed the Canadians on technical marks and program components in their clean and lively tango program.

“It’s been a long 15 years we’ve been together, and just building toward this moment,’’ White said. “I think we kind of knew it would come eventually. But you have to make it happen on the ice.’’

Virtue and Moir were more aesthetically adventurous in a program that smoothly moved from Latin music to smoky jazz to a drum fusillade and included a dramatic upside-down lift.

“We set out to challenge ourselves and to push the boundaries of ice dancing,’’ Virtue said. “The program is unlike anything we’ve ever done before and I think unlike anything the ice dance world has ever seen. We’re really proud of what we’ve accomplished.’’

All of the 2010 champions entered this year, and none of the defenders prevailed. Mao Asada of Japan finished sixth after an error-filled short program. Daisuke Takahashi finished sixth in the men’s, overwhelmed in a field won by Canada’s Patrick Chan, who set three world records in the process. Aliona Savchenko and Robin Szolkowy won the pairs, with 2010 champions Pang Qing and Tong Jian of China settling for bronze.