The United States Ryan Crouser added 19 centimetres to own world record in the shot put at the Los Angeles Grand Prix ©USATF

America’s Ryan Crouser added 19 centimetres to his own world shot put record at the Los Angeles Grand Prix with a fourth-round throw of 23.56 metres.

The record has yet to be ratified and the 30-year-old world and double Olympic champion will be hoping for a case of third time lucky after seeing two previous "world records" annulled.

Crouser thought he had thrown 23.38m, a centimetre more than his 2020 record, at last year's Millrose Games, only for it to emerge that the measuring laser was faulty.

On February 18 this year he reached 23.38m again in Idaho - but this time the circle was found to exceed regulation size.

This year Crouser has developed a new technique involving an extra sidestep during his rotation, and in this World Athletics Continental Tour Gold meeting at the University of California’s Drake Stadium everything, in his word. "clicked" as he also threw 23.23m and 23.31m.

"I finally saw the spread I've been looking for," he said.

"That's what has me the most excited."

World and Olympic pole vault champion Mondo Duplantis won on countback with 5.91m after he and home vaulter Sam Kendricks, the 2017 and 2019 world champion, failed at 6.01m.

Nigeria's world champion and record holder Tobi Amusan finished last in a women's 100m hurdles won by Puerto Rico's Jasmine Camacho-Quinn in 12.31sec.

Marileidy Paulino set a Dominican Republic record of 48.98 in the women's 400m.

In the women's 100m the Ivory Coast’s Marie-Josee Ta Lou and home sprinter Sha'Carri Richardson ran 10.88 and 10.90 respectively in the heats but did not contest a final won by Morolaki Akinosum of the United States in 10.98.

An explanation was not given for Ta Lou’s withdrawal, Richardson reportedly experienced cramps.

The fact two of the biggest names at the meeting organised by USA Track & Field (USATF) pulled out of a much-anticipated head-to-head at a meeting designed to helped raise interest in the sport before the 2028 Olympic Games in Los Angeles followed the withdrawals from the meeting last week of Olympic 400m hurdles gold medallist and world-record holder Sydney McLaughlin-Levrone and world and Olympic 800m champion Athing Mu.

“If you look at it from a purely commercial standpoint, it obviously contributes to a little bit of frustration in terms of marketing the event,” Max Siegel, USATF’s chief executive, told the Los Angeles Times.

“You look at it from keeping the athletes safe and healthy and prepared, I mean, we have bigger events, so a lot of these competitions are meant to get them fitness ready.”

“So, you do understand that stuff happens.”