|Dates: 23 July-8 August Time in Tokyo: BST +8|
|Coverage: Watch live on BBC TV, BBC iPlayer, BBC Red Button and online; Listen on BBC Radio 5 Live, Sports Extra and Sounds; live text and video clips on BBC Sport website and app.|
After huge success at the World and European Championships in recent years, the mixed 4x100m medley relay made an exciting Olympic debut.
The hotly-anticipated event sees teams made up of two men and two women, with each swimming 100m in either backstroke, breaststroke, butterfly and freestyle.
The order of strokes must remain the same, but teams decide which athletes, male or female, swim in each.
Fresh from 1winning 100m breaststroke gold, Adam Peaty returned to the pool in Thursday's heats as the world's best male and female global stars went head-to-head for the first time in this event at an Olympics.
Team GB are among the favourites after claiming a stunning gold at the European Aquatics Championships in May.
The British quartet in Tokyo broke their own European record as they reached Saturday's final in style.
Peaty, Kathleen Dawson, James Guy and Freya Anderson set the fastest time in the heats - 2.27secs quicker than any other team.
Peaty, 26, is excited to see the sport evolve as he said: "It's a popular event at every championship, so for it to come to the Olympics shows what swimming can be.
"It doesn't have to stay the same as it's been for the last 100 years. It can develop and evolve to what the modern world is.
"It's a new race and it's entertaining. You might be leading by 100m then someone else takes over which is the fun of it."
Team GB will be joined in the final by world record holders China, world champions Australia, the United States, Netherlands, Italy, the Russian Olympic Committee team and Israel.
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