Beck won the women's 5 kilometres in 59min 31.70sec, from Sharon van Rouwendaal of the Netherlands who clocked 59:32.70 and Tokyo Olympic gold medallist Ana Marcela Cunha of Brazil who claimed bronze in 59:35.60.

Beck became the third woman to claim both titles at a World Championship after swimming a strong second half of the race to claim victory.

"I tried to save a bit of energy in the first lap but there are only three laps, so you cannot be saving too much energy," Beck said.

Beck lost ground after a collision and had to swim hard to catch the pack in the mid part of the race.

"I hit something during the race and got something in my eye, because of that I dropped back a lot of places after the first buoy," Beck explained.

She eventually caught her rivals and stormed through to win by only one second.

"I’m really happy, I didn't believe I could win a medal in the 5km after the hard 10km race," Beck added.

"Mentally it's not easy, but I'm really happy that I could win the 5km, I never would have thought of it."

In the men’s race, Olympic gold medallist Florian Wellbrock also completed the double.

He won in 53:58.00 from Italy’s Gregorio Paltrinieri who finished in 54:02.50.

Another Italian, Domenico Acerenza, took bronze in 54:04.20.

"Today, the conditions were much harder than the 10km,” Wellbrock revealed.

"Today I started really fast, I tried to push directly after the start and I think it was the key for the win today,” 

It was his fifth World Championship gold in open water swimming.

In the diving pool, China remain on course to sweep the board of gold medals after their victory in the team event.

Si Yajie and Zheng Jiuyuan on the 3 metre board and Zhang Minjie and Bai Yuming on the 10m highboard achieved a total score of 489.65 to take gold.

"I have participated in many international competitions but still I get very nervous, like it was my first time," Si, who at 24 is the oldest of the Chinese quartet, said.

Mexico began with Gabriela Agundez Garcia and Jahir Ocampo Marroquin on the 3m board, but surged into silver after Gabriela Agundez Garcia in the 10m pulled off the dive with the greatest degree of difficulty in round four.

Her team mate Randal Willars Valdez executed a fine dive in round five and the Mexicans made sure of the silver in the final synchro round with a score of 455.35.

It left Germany’s quartet Christian Wassen, Moritz Wesemann, Lena Hentschel and Timo Barthel to hold on for bronze scoring 432.15.

Spain took gold in the artistic swimming team technical event with a score of 281.6893.

Silver went to Italy who scored 274.5155 while the United States claimed bronze with 273.7396.