Olympic gold and silver medallists Tom Dean and Duncan Scott continued their imperious form in the pool as they combined to help Team GB win the 4x200m freestyle relay and the team’s fifth gold overall in Tokyo.
The quartet came within 0.03 seconds of breaking the world record after a stunning performance that blew away the rest of the field.
They had been in third going into the second leg but James Guy accelerated them ahead of the rest of the field and they never looked like being caught.
Another medal was added in the men’s quadruple sculls but overall it was a disappointing day in the rowing.
Some dodgy steering in the last 500m of the men’s four almost had the British boat careering into the Italians, leaving Team GB forlorn in fourth.
A visibly emotional Oliver Cook said after the race: “I feel I screwed up a bit and as I was closing in at the end and taking big strokes going for the line I forgot the steering.”
It means the lineage of gold’s that had been won in the men’s four by Team GB at every Olympics since Sydney in 2000 was broken.
Andy Murray’s bid for a third Olympic gold ended as he and Joe Salisbury were beaten in the men’s doubles by Marin Cilic and Ivan Dodig.
It still remains Team GB’s best ever start to an Olympic Games.
Looking ahead to the rest of the day, highlights include Great Britain’s men’s sevens bronze medal match against Argentina.
Meanwhile Charlotte Dujardin, strong off the back of her bronze in the team dressage final, is looking to become the first British woman to win gold at three Games.