Olympic shot put champion Ryan Crouser shattered one of the oldest world records in athletics on Friday, producing a mammoth heave of 23.37m as the US track and field trials got underway in spectacular fashion.

The 28-year-old Crouser obliterated compatriot Randy Barnes’ world record of 23.12 set in 1990 with his fourth throw of a gripping final at Hayward Field in Eugene, Oregon.

Crouser had already eclipsed Barnes’ world indoor record earlier this year, throwing 22.82 at a meeting in Arkansas.

But the charismatic 2016 Olympic gold medallist had been moving ever closer to Barnes’ outdoor record, hinting it was within his reach last month with a world-leading 23.01.

Crouser had signalled he was ready to take a crack at the world record in Friday morning’s qualifiers, with a hefty 22.92 throw – what was then the fifth-longest throw in history.

In Friday night’s final, Crouser took his time, warming up with throws of 22.61, 22.55 and 22.73.

Then with his fourth effort, he unleashed his world record toss to punch his ticket to next month’s Tokyo Olympics in style.

Unsurprisingly, that throw gave him victory, with old rival Joe Kovacs, the 2019 world champion, finishing second with 22.34. Payton Otterdahl was third with a throw of 21.92.

“The second it left my hand I knew it was good,” Crouser said of his world record toss.

“It’s been a lot of work and dedication,” Crouser said of his long pursuit of the world record. “It feels like a weight has lifted.

“I felt really, really confident coming in, but it wasn’t an expectation.

“The times I’ve come up short it was me just getting a little bit tight, and trying to force it. I stayed loose I stayed relaxed and executed my game plan that I had coming in, and that was the key for me finally doing it.”

Crouser’s performance was the outstanding display of an entertaining opening day for the June 18-27 trials, where places on the US Olympic team are up for grabs.

Watch Crouser’s record-breaking shot below:

(With AFP inputs)