Fran Halsall fed off the anger of her disappointment in the 100 metres freestyle on Thursday night to storm into the semi-finals of the 50m at the Aquatics Centre.
The 22-year-old had long been fancied for a medal in the blue riband two-length event but she finished sixth, 0.22 seconds off the rostrum.
The Loughborough ITC swimmer was desperately disappointed after the race and vowed to use her anger in the race known as the splash and dash.
Halsall was third fastest in 24.61 and admitted she had been angry before the race.
She said: "I am in a very steely, determined mood at the moment. I am like, this is it, I have nothing to lose now.
"There are literally six girls who can get a medal. We are all very close. If I make it through to the final, no way any of them will beat me! That's for sure."
After only about five hours sleep, Halsall planned to go back to the village for a nap before returning for Friday night's semi-finals when the crowd will be at fever pitch with Rebecca Adlington looking to defend her 800m freestyle title.
"It's amazing and for a 50, it's definitely going to help when everyone goes mental. It's absolutely mental. I don't think it could have been any better. I love it."
Amy Smith was tied with two other swimmers in 16th to force a swim-off.