Clocking a time of 51.90sec, McLaughlin took the world record from the second-placed finisher in the race, Dalilah Muhammad, who ran a season's best of 52.42, at Hayward Field. 

McLaughlin's run made her the first women to run under 52 seconds in the event, having smashed Muhammad's previous best of 52.12 from 2019.

Both will head into Tokyo 2020 as the favourites in the discipline and are set to be joined by bronze medallist Anna Cockrell who ran a personal best of 53.70 to take the final spot.

Noah Lyles ensured he would be going to the Games after a disappointing seventh in the 100m final, by winning the men's 200m in a 2021 world leading time of 19.74.

He was followed by three athletes who all recorded personal bests - the closest challenger being Kenny Bednarek who ran a new best of 19.78.

Seventeen-year-old Erriyon Knighton took bronze and the third spot on the team in 19.84 - further improving on Usain Bolt's world junior record - ahead of Fred Kerley, who was aiming to double up in 100m and 200m at Tokyo 2020.

Kerley made the switch from the 400m, in which he won the bronze medal at the 2019 World Athletics Championships.

Although unable to make the top three, his new personal best of 19.90 makes him the third man to break the 10, 20 and 44-second barriers in 100m, 200m and 400m after South Africa's Wayne van Niekerk and team mate Michael Norman.

The women's 800m final provided five personal bests in the top six as teenager Athing Mu set a new best and a world lead of 1min 56.07, making it the second-fastest time ran by an American.

That American record belongs to Ajee Wilson, who confirmed her spot at Tokyo 2020 after finishing third behind Mu and Raevyn Rodgers.

Although not on the plane to Tokyo, Michaela Meyer, Chanelle Price and Allie Wilson all recorded personal bests and Kate Grace and Hanna Green also broke two minutes in the final - showing the incredible depth of the field in one of the fastest races in the event's history.

Perhaps the performance of the day came from JuVaughn Harrison, who won both the high jump and long jump golds in the same night.

After clearing all his efforts at the first time, he finally bowed out with a best of 2.33 metres, defeating Darryl Sullivan on countback.

Shelby McEwen took third and will join the pair in Tokyo after clearing 2.30m ahead of London 2012 champion Erik Kynard on 2.27m.

Later performing in the long jump, Harrison set a personal best in the third round with an effort of 8.47m to win a second spot at the Olympics in a matter of hours.

Marquis Dendy confirmed his spot too with a second round jump of 8.38m, while Steffin McCarter equalled his personal best of 8.26m to qualify too in third.

Rio 2016 champion Jeff Henderson's dreams of defending his Olympic title were dashed as he could only manage 8.08m for sixth.

Proving to be a tactical maverick this season, Cole Hocker won the men's 1500m in a personal best of 3:35.28 ahead of Olympic champion Matt Centrowitz in a photo finish.

Yared Nuguse booked his spot in third ahead of Craig Engels - who both had the Olympic standard.

Hocker has not made the standard of 3:35.00 and will now need to rely on his World Athletics ranking to see if he can make it to the Games, which looks likely as he has the highest ranking among those without the standard.

Rio 2016 silver medallist Paul Chelimo sealed his spot in the men's 5,000m at Tokyo 2020 with a win in the trials final in 13:26.82, winning a sprint to the line ahead of Grant Fisher and Woody Kincaid who will also compete at the Olympics.

Finally, Annie Kunz claimed the win in the women's heptathlon following a dramatic 800m.

Kunz was two points behind leader Kendell Williams going into the race and Erica Bougard was 100 points off the lead, with all three still having a shot at claiming victory. 

Kunz's time of 2:15.24 was enough for sixth, finishing more than a second ahead of Williams in eighth as Bougard was five seconds ahead in second.

Finishing with a personal best of 6,703 points, Kunz claimed the title win, while Williams achieved her highest score of 6,683 ahead of Bougard 6,667.

All three have qualified for the Olympics by finishing in the top three.