The South African sprinter, Van Niekerk, clocked a world leading 43.62sec in Lausanne, the third fastest time of his career. Van Niekerk's 43.62sec performance in Lausanne broke the long standing Michael Johnson's meet record.
"I didn't come with a specific time in mind but I am pleased with this result," Van Niekerk said.
"I do have a love-hate relationship with the 400m, but I always try to approach it with a positive mindset, not setting myself any limits.
"And the performances keep me going along, which keeps me passionate about what I do." he added.
Russia's Maria Lasitskene was another athlete that broke the Diamond League record on Thursday. The 24-year-old Lasitskene cleared massive PB of 2.06m in the women's high jump to set a new Diamond League record and to equal Russian record. Lasitskene also extended her winning streak this year to 16 competitions.
The 35-year-old Amercian Sprinter Justin Gatlin of the United States sprinted to victory in the men's 100m in 9.96sec.
"I didn't have a great start," said Gatlin.
"I'm not at my A-game at the moment and that sows I'm a human.
"I am still a competitor Now I will be able to go back to training knowing that my bases are are in place."
World champion Dafne Schippers of Netherlands managed to win the 200m race in 22.10sec. Marie-Josee Ta Louo of Ivory Coast took second in a new new national of 20.16sec.
Genzebe Dibaba attempted Svetlana Masterkova's women's mile recrod of 4:12.56. The Ethiopian super star ended up winning the race in a new world leading time of 4:16.05.
"I felt good during the first part of the race. I had good legs up until 1 200m. And then it blocked," Dibaba said.
"It's a pity as the conditions were good. I need to train some more to have some freshness at the end of the race."
In the women's javelin, Olympic champion Sara Kolak of Croatia threw a massive world leading 68.43m to beat Czech Republic's Barbara Spotakova (67.40m) into second place.
Sam Kendricks of the United States cleared 5.93m in the pole vault for the win. Poland's Pawel Wojciechowski took a surprise second place with a new PB of 5.93, while world record holder Renaud Lavillenie of France with 5.87m concluded the men's pole vault podium.
American women dominated both hurdle races in Lausanne. Ashley Spencer won a talent stacked women's 400m hurdles race in 53.90, while Sharika Nelvis clocked a new SB of 12.53sec to win the women's 100m hurdles.