ABU DHABI (XINHUA) - Brazilian Nicholas Santos showed age is just a number after winning the men's 50m butterfly at the age of 41 while Margaret MacNeil triumphed in the women's 50m backstroke with a world-record time at the Fina short-course World Swimming Championships on Monday (Dec 20).

On the penultimate competition day, Santos starred in the 50m butterfly final, where his rivals were at least 11 years younger than him.

The veteran was only 0.12sec behind the championship record, which was also set by him three years ago in Hangzhou, China, as he comfortably defended his title in 21.93sec.

"I have my own company. I have to work. I also have a son to take care of, so I'm changing my life now," said Santos, who also won the same event at the 2012 edition.

"But at the same time, the competition still gives me great feelings.

"I simply love races. I still cannot live without them."

China-born Canadian MacNeil, 20 years younger than Santos, contributed another highlight as did Japan's Daiya Seto on Monday.

The reigning world and Olympic champion in the 100m butterfly showed her power in the 50m backstroke this time, slicing 0.33sec off the previous world record - set last year by Dutch swimmer Kira Toussaint - to win her first individual gold at the meet in 25.27.

Seto, 27, won his fifth short-course world title in the 400m individual medley with a time of 3:56.26, equalling the competition record by Britain's James Hickman, who also won five times in the 200m butterfly.

He said: "This event is my favourite and I really wanted to win it for the fifth time, so I am really happy to have done that.

"Now I want to win my sixth world title and hope to be an Olympic champion at the Paris 2024 Games."

China's Tang Qianting, 17, edged out Sophie Hansson, 23, of Sweden to win the women's 100m breaststroke in 1:03.47, but fellow Chinese Yu Yiting, 16, had to settle for silver in the women's 200m individual medley, with Canadian Sydney Pickrem, 24, touching the wall first in 2:04.29.