Tom Dean stormed to victory in the men's 200 metres freestyle and Great Britain were left to celebrate a famous one-two after Duncan Scott collected silver at the Tokyo Aquatics Centre.
Dean, who twice contracted coronavirus last year, was third heading into the final 50 metres while Scott was down in sixth at the halfway stage, but the pair finished strongly.
Dean finished in a time of one minute and 44.22 seconds, edging out his British compatriot by 0.04secs, with Brazil's Fernando Scheffer claiming bronze a further 0.4s back.
Scott, a bronze medallist over the distance at the 2019 World Championship, was heavily fancied coming into this showpiece after setting the quickest qualifying time in Monday's semi-finals, with Dean fourth fastest.
But Dean was into his stride almost immediately from lane six and after pipping his GB team-mate, he raised both hands and stared at the screen confirming his win almost in a state of disbelief.
This result marks the first time two British male swimmers have shared an Olympic podium since London 1908.
Dean told the BBC: "I knew it was going to be a dogfight. I didn't know how people were going to swim it.
"I just want to say thanks to everyone back home. I'm just lost for words. It's amazing."
Scott added: "A massive credit to Dean. That was unbelievable. Olympic champion. He's come along so far in the last 18 months, it's a pleasure to watch.
"It's great to be able to say he's a good mate out of the pool and it's great to be able to compete against him as well."
