Tunisian swimmer Ahmed Hafnaoui took a shock gold medal in the men's 400m freestyle on Sunday.
The 18-year-old won from the outside lane after qualifying slowest, but finished with stunning pace to beat Australia's Jack McLoughlin with a time of three minutes 43.36 seconds.
"I just can't believe it. It's a dream and it became true. It was great, it was my best race ever," said Hafnaoui.
It was Tunisia's fifth ever gold - and third in swimming.
US swimmer Kieran Smith took bronze at the Tokyo Aquatics Centre.
Hafnaoui, son of former Tunisian national basketball player Mohamed Hafnaoui, competed in the 2018 Youth Olympic Games, finishing eighth in the 400m and seventh in the 800m.
In 2019, he told Tunisian outlet La Presse he was aiming to win his first gold medal at the 2024 Olympic Games in Paris.
Hafnaoui will have a second shot at gold as he competes in the 800m freestyle, with heats starting on Tuesday.

Hosts Japan also celebrated a surprise gold in the women's 400m individual medley, as Yui Ohashi pipped two Americans to the top step of the podium.
"It doesn't feel real. It is like a dream for me," said the 25-year-old.
"I couldn't go to the Rio Olympics, so for the past five years this became a big dream for me. This accomplishment is amazing."
Latest Stories
-
Gov’t reforestation project boosted with GH₵1m donation from Ghacem Ltd
12 seconds -
Mahama breaks ground for Phase II of Blekusu Coastal Protection project
60 minutes -
Illegal miners seize farmlands, pollute Black Volta tributary in Bole-Bamboi
1 hour -
NPP: We’re not broken, we’re fighters and servants of Ghanaians – Justin Frimpong Kodua
2 hours -
Let us learn from our flaws – Bawumia urges NPP members
2 hours -
NPP will never forget to prosecute perpetrators of Ablekuma North electoral violence – Bawumia
2 hours -
Our foundation and strength lies in building a diverse, united party – Bawumia
2 hours -
Bawumia charges NPP delegates with emotional, ‘mixed feelings’
2 hours -
Transformative achievements of Kufuor, Akufo-Addo will stand the test of time – Bawumia
2 hours -
Ghanaians must see the lessons we have learnt – Bawumia
2 hours -
Tribalism and religious bigotry should have no place in NPP – Bawumia
3 hours -
Ambassador Sam Pee Yalley
3 hours -
Stop the internal attacks and focus on the ills of the NDC – Bawumia urges NPP members
3 hours -
We’re surprised EC decided to rerun Ablekuma North – NPP
3 hours -
We’ll not allow 2024 defeat to destroy NPP – Afenyo-Markin
3 hours