Britain had won gold at the last five Olympics.
Great Britain’s run of five successive Olympic golds in the men’s four came to an end as they missed out on a medal altogether in Tokyo.
But after trying to chase down オーストラリア who set a fierce pace from the start, the team of Oliver Cook, Matthew Rossiter, Rory Gibbs, Sholto Carnegie faded at the end and missed out on a podium place as they were overtaken by Romania and Italy.
The British boat briefly left its lane in the closing stages, almost colliding with Italy.
It followed two other fourth-placed finished for the Team GB at Sea Forest Waterway on Wednesday.
Graeme Thomas and John Collins narrowly missed out on a medal in the final of the men’s double sculls.
The British duo pushed hard to catch China in bronze medal position over the final stages in breezy conditions but were unable to close the gap.
Gold went to French double Hugo Boucheron and Matthieu Androdias by just 0.2seconds from Holland.
There was similar agony for the women’s four of Rowan McKellar, Harriet Taylor, Karen Bennett and Rebecca Shorten.
But their disappointment was joy for the Irish quartet of Aifric Keogh, Eimear Lambe, Fiona Murtagh and Emily Hegarty, who won their country’s first medal of the Games by pipping the British women to bronze.
Australia claimed gold in another close finish ahead of Holland.