Steven Gardiner made it a world and Olympic double by winning the men's 400 metres at Tokyo 2020 on a day where Hansle Parchment shocked Grant Holloway to win the 110m hurdles.
Ryan Crouser defended his shot put title from Rio 2016, while Pedro Pablo Pichardo and Katie Nageotte were also among the gold medal winners at the Tokyo Olympic Stadium.
Here's a round-up of Thursday's best action in athletics.
GARDINER FOLLOWS UP DOHA TRIUMPH
Defending 400m champion Wayde van Niekerk, who suffered a horrific knee injury in 2017, was not in the final and Gardiner displaced the South African in the Tokyo humidity.
The man from the Bahamas won gold in Doha at the world championships two years ago and timed his race to perfection in the Japanese capital, storming ahead from the final bend and passing the line in a time of 43.85s.
Anthony Zambrano of Colombia was second, while 2012 champion Kirani James added Olympic bronze for Grenada.
Just a night on from Andre De Grasse becoming men's 200m champion, Canada had more reason to celebrate as Damian Warner earned an Olympic record 9,018 points to win the decathlon. Kevin Mayer of France took silver ahead of Australia's Ashley Moloney.
In the heptathlon, Nafissatou Thiam defended her gold from Rio 2016 – the Belgian accruing 6,791 points. Dutch pair Anouk Vetter and Emma Oosterwegel were second and third.
PARCHMENT BEATS HOLLOWAY IN HUGE SHOCK
Possibly the biggest shock on the track of Tokyo 2020 so far arrived in the men's 110m hurdles, where world champion and clear favourite for gold Holloway had to settle for silver.
Instead, first place was taken by Jamaica's Parchment, an outsider on paper who stormed through when Holloway's momentum appeared to stall at the last two hurdles to win in a time of 13.04 seconds.
There was further upset for Team USA in the men's 4x100m relay, where a shock sixth-placed finish in their heat meant they missed out on the final.
Massimo Stano was a surprise winner of the men's 20km walk race, a strong finish seeing him beat well-fancied Japanese duo Koki Ikeda and Toshikazu Yamanishi.
With his victory, Italy have won three athletics gold medals at the same Games for the first time.
CROUSER LIVES UP TO THE BILLING IN AN OLYMPICS QUIRK
Crouser lived up to his billing as favourite in the men's shot put and in some style to defend his title from Rio 2016.
The American equalled or bettered his previous Olympic record with each of his six throws, with the winning distance marked at 22.93m.
World Champion and countryman Joe Kovacs took silver, while New Zealand's Tom Walsh was third. Incredibly, this was the exact same podium as at Rio 2016 – the first time in Olympics athletics to have the exact same repeat of a podium.
Pichardo was equally brilliant in taking home the men's triple jump gold. His effort of 17.98m represents the second-best winning jump in Olympics history and was personal redemption for the Portuguese, who missed out in Rio five years ago.
China's Zhu Yaming earned silver with a lifetime-best jump of 17.57, with Hugues Fabrice Zango of Burkina Faso in third.
Nageotte earned a nice piece of history in winning women's pole vault gold for the United States. No woman or man has ever missed with their opening two attempts and gone on to win Olympic gold.
But Nageotte cleared 4.90m, a height no one else in the competition could match. Anzhelika Sidorova – the 2019 world champion – claimed silver for the Russia Olympic Committee, with Holly Bradshaw of the United Kingdom taking bronze.