Swimming pair Michael Jamieson and Andrew Willis broke records as they booked their places in the 200 metres breaststroke final on Wednesday night.
Scotland's Jamieson set a new British record in the first semi-final with a time of two minutes 8.20 seconds before Willis responded in the next semi by breaking the English record in a time of two minutes 8.47 seconds.
Jamieson was the fastest qualifier while Willis, who finished second in his semi-final, was the third quickest to make it through to the final, giving hope of British medal glory in the Aquatics Centre.
The former proved he is a real contender in the 100m breaststroke with an astonishing time of 2:08.20 to elevate himself into the world all-time top 10.
Jamieson - who turns 24 the day after the swimming programme ends - said: "I knew I was going to have to improve on this morning to get into the final. I am swimming full of confidence and a swimmer with confidence racing in front of this crowd, it makes it a lot easier to swim fast.
"I could really hear those guys urging me home in the last 50 and I'm hoping they can make even more noise tomorrow night and myself and Andrew can shave some more time off."
Willis added: "To come down the last length and feel that roar, it's like they are pushing you, driving you on, it gives you the sense to really go for it. I have a middle lane in the final, I couldn't really ask for much more."
Hannah Miley was seventh as 16-year-old Chinese sensation Ye Shiwen won the Olympic 200m individual medley title. Fellow Team GB swimmer Caitlin McClatchey also finished seventh in the 200m freestyle final.
Pre-Games medal hope Ellen Gandy went out in the morning heats of the 200m butterfly but Jemma Lowe progressed to the final of the same event, coming through her semi-final in two minutes 7.37 seconds.
The men's 4x200m freestyle relay team of Robbie Renwick, Ieuan Lloyd, Rob Bale and Ross Davenport were sixth in their final.