Russia's Nikita Nagornyy expected a sleepless night in Stuttgart after winning the men's all-around world title on Friday - worrying about his wife who is also competing this weekend at the world gymnastics championships.

Nagornyy, 22, pipped defending champion Artur Dalaloyan to gold as Russia took first and second.

He also earned the first individual world title of his career having claimed bronze behind Dalaloyan in Doha last year.

"I am very happy. It's better than last year, it's gold-silver for us, instead of gold-bronze," joked Nagornyy.

However, Nagornyy expected to spend Friday night worrying about wife Daria Spiridonova, who qualified in second place for Saturday's uneven bars.

Spiridonova, 21, won the 2015 world title but faces stiff competition in the final from U.S. star Simone Biles and reigning champion Nina Derwael of Belgium.

"I am very nervous for her, more than I am for myself," he said, with the couple who married in December to spend the night apart.

Nagornyy is also in action again on Saturday in the floor exercise.

"We try not to disturb each other during competition and I will probably only see her briefly in the morning," he added.

Nagornyy finished 1.607 points ahead of Dalaloyan while Ukraine's Oleg Verniaiev, who had surgery on both ankles in January, took bronze.

"I am so very happy, I didn't come here to win and didn't expect to get on the podium. I still need more time," said Verniaiev.

Dalaloyan paid the price after a rare mistake on his landing from the vault saw him finish 18th in the discipline.

China's Xiao Ruoteng, the 2017 world champion and 2018 silver medalist, finished fourth after a fall on the horizontal bar left him in 21st place in that event.

Nagornyy had the highest score in two of the six events – the vault and rings – and finished in the top three on the floor and parallel bars.

It was his second gold medal in Stuttgart after Russia won the team competition on Wednesday.

Japan's Olympic champion Kohei Uchimura, who has won the all-around world title a record six times, is missing from Stuttgart after struggling for form after injury.