Veteran Yamile Aldama reached the final in the triple jump with her first leap in qualifying of 14.45m at the Olympic Stadium.
Aldama, who had heavy strapping on the right shoulder she injured in Rome on May 31, said: "I have no words to describe the crowd. I've been to five Olympic Games and the qualifying is never like this."
Defending Olympic champion Christine Ohuruogu, Shana Cox and Lee McConnell all advanced to the semi-finals of the 400m, while world champion Dai Greene, training partner Jack Green and European champion Rhys Williams eased into the next round of the 400m hurdles.
Greene qualified fourth fastest overall, with world number one Javier Culson of Puerto Rico quickest in 48.33, and said: "It was relatively easy. I struggle to get up for the heats usually so I just had to make sure I qualified as winner of my heat."
Britain's Alex Smith also made the final of the hammer, but thought he was destined to miss out after finishing only 10th in the first qualifying pool.
"It was just such a brilliant experience being out there, though I could have done better," Smith said. "But it was my first major championships and I am proud of what I've done. I went over to speak to my coach and I couldn't hear what he was saying because everyone was cheering me."
Only one man threw further than Smith in the second pool, meaning his best throw of 74.71m took him into the final as the 11th of 12 qualifiers.
There was disappointment for Carl Myerscough and Stuart Stokes in the shot and 3,000m steeplechase as they bowed out of their respective competitions.