The women’s 4x100m swimming relay team narrowly missed out on a medal on Saturday night.
They finished fifth behind eventual winners Australia.
Rotherham’s Becky Turner had finished the first morning of heats in the aquatics centre with a flourish as she dragged the British relay squad back from sixth to tied fourth with Sweden.
That was enough to seal the squad’s place in tonight’s final with the joint seventh fastest time.
But Turner was left out of the final squad and replaced by Fran Halsall.
And although they were third at the halfway mark, the hosts missed out on a medal and finished fifth.
Nevertheless, Turner, 19, was heartened by her performance and is encouraged by her form going into the 200m freestyle and the 4x200m relay.
“Swimming well today let’s me know I’m in good shape and I’ve got a lot to give in the individual events as well,” she said.
The crowd played their part on an enthralling opening morning in the aquatics centre, cheering raucously every home swimmer who competed.
Turner, whose swam her 100m leg in 54.75secs, added: “It’s pretty cool having them cheering you on, knowing everyone wants you to swim well.”
Yorkshire swimmer Joe Roebuck made a disappointing start to his Olympic campaign, but is confident in his ability to bounce back over the coming days.
The 27-year-old from Rotherham failed to qualify for the tonight’s final of the 400m individual medley in an atmospheric aquatics centre.
Roebuck shot out of the blocks to lead his heat after a quick first 100 in the butterfly, but by the second split his backstroke had seen him drop to seventh.
He eventually finished eighth in a time of 4.20:24, fully six seconds down on his personal best.
But with the 200m butterly heats to come on Monday morning, and the 200m IM on Thursday, he is confident that all is not lost.
“The butterfly felt really easy which is a great positive with the 200m fly coming up, and I feel strong going into that,” said Roebuck.
“I feel I’ve got the speed for both remaining races.
“I prioritise the other two races but it was nice to get the first race out of the way, to get over the nerves.
“I would have liked to have done a much better job being the first Briton out to help kickstart the team but it was not to be.”
Middlesbrough’s Aimee Willmott, 19, arrived at London 2012 with a unique ambition - to beat her father.
Stuart Willmott finished 15th in the 400m IM at the Los Angeles Games of 1984.
Twenty-eight years to the very day, Aimee Willmott finished 11th, eclipsing her father’s effort.
She said: “I’m really, really happy with that, I nearly reached the final as well, but at least I can rub it in my dad’s face.
“He told me to enjoy the whole occasion, because it’s a once in a lifetime thing.
“I gave it everything I could as I was being roared on by the crowd but I just couldn’t hold the girl in fifth off.
“I knew the final would be a long shot but that’s my fastest ever morning swim so I’m proud that I stepped up on the big day.
“I’ve always been better at the first two, and I’ve always had that edge in the backstroke.
“But next year I need to work on holding my breaststroke and staying in a higher position.
“If I can work on the last 200 metres of the race then there’s only good things to come.”