Helen Glover's return to rowing did not have a fairytale finish as the mother-of-three and Polly Swann finished fourth in the Olympic women's pair.
Glover, 35, was aiming to become the first British woman to win gold medals at three Olympics.
"We're pleased with the result, it shows our hard work," said Glover.
Meanwhile British pair Emily Craig and Imogen Grant missed out on a medal by 0.01sec in a thrilling lightweight women's double sculls.
Craig and Grant finished fourth in a race which British five-time rowing medallist Dame Katherine Grainger described as "a great advert" for lightweight rowing.
Italy pipped France to gold with the Netherlands edging out the British pair for the bronze - with the four crews separated by just half a second.
"Emily Craig and Imogen Grant haven't put a foot wrong but it just came down to one final stroke at the end," said Grainger, who won medals in five successive Games between 2000 and 2016.
The narrow misses for the two British crews on Thursday mean Team GB has finished fourth in five events at the Sea Forest Waterway in Tokyo.
Glover is the first mother to make the nation's Olympic rowing team and gave birth to twins last year.
Her comeback began last March, when the Tokyo Games were postponed for 12 months until this summer because of the coronavirus pandemic.
She reunited with Swann, who partnered Glover when Heather Stanning took a break after London 2012.
"Right now I'm pleased we put everything on the line," said Glover, who won gold at London 2012 and Rio 2016.
"We knew it was always going to be a really big final to be in, getting here was a tough route and knew if we got over the line having spent everything, looking back on the way we got here, we'd be pleased."
Glover and Swann should be "incredibly proud" of their achievement, said Grainger.
"They took on an enormous challenge and they have done it in style," added Grainger, who won medals in five successive Games between 2000 and 2016.
"They have raised awareness and talked about issues. They were very, very competitive."
Swann, a 33-year-old NHS doctor, was also seeking to cap a stunning comeback after taking a break to focus on her medical career.
New Zealand won gold with the Russian Olympic Committee taking silver and Canada holding on for bronze.
"That is still an outstanding result for Glover and Swann," said two-time Olympic gold medallist James Cracknell.
"What cost them a medal was why you train for four years, you lose the spring at either end of the race - the start and the sprint finish. They had a lack of top speed."
