Dai Greene moved safely through his Olympic 400m hurdles heat on a good first morning for Britain's athletes.
Fellow medal contenders
also progressed as the packed stadium created a wonderful atmosphere for home athletes.
World champion Greene made light of a tricky draw to win the third heat from lane one in a comfortable 48.98 secs.
He is joined in Saturday's semi-finals by world number one Javier Culson and Olympic champion Angelo Taylor.
also made it through after coming through their heats in contrasting fashion.
Green, who trains with Greene in Bath under the legendary Malcolm Arnold, qualified automatically in second from his heat, while Williams made it through as a fastest loser.
Ohuruogu qualifies for 400m semi
Beijing gold medallist Ohuruogu ran a typically well-judged race to take second behind the Francena McCorony of the United States in 50.80 secs, although the fact she let the lead slip may give her a slightly worse lane draw in Saturday's semis.
Her main rival, American Sanya Richards-Ross, breezed through as winner of the fourth heat despite a sudden rain shower leaving the track covered in puddles.
The 40-year-old Aldama, who went straight into Sunday's triple jump final with her first effort of 14.45m, spoke for many when she said: "This is my fifth Olympics and I've never experienced a crowd like this in the qualifying round."
both went through to the 400m semis, finishing third in their heats.
went out in shot put qualifying, with his best of 18.95m placing him just 29th, well outside the top 12 required.