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Video - Mixed fortunes for GB long jumpers
Britain's Greg Rutherford made life easy for himself by reaching the Olympic long jump final with his first qualifying effort.
Rutherford jumped 8.16m, one centemetre better than the automatic qualifying mark, but Chris Tomlinson went out.
Sprinter Jeanette Kwayke reached the semi-finals of the 100m but Montell Douglas missed out.
And Christine Ohuruogu, Nicola Sanders and Lee McConnell all breezed into the next round of the 400m.
Rutherford, the European silver medallist last year, finished as the third-best qualifier behind Greece's Louis Tsatoumas (8.27) and Cuba's Ibrahim Camejo (8.24) but Tomlinson, who passed a late fitness test to compete, missed out after a best of 7.70m.
Kwakye finished third in her 100m heat in 11.18 seconds behind Jamaica's Shelly-Ann Fraser to advance to Sunday's semi-finals.
Kwayke told BBC Sport: "That's a personal best. I seem to do it when it matters and I'll take that but I have to go faster if I want to get into the final.
I just didn't stick to my race plan and got pushed about a bit
800m runner Marilyn Okoro
"I'm pretty confident I can pick it up when it matters. Mentally I put myself up there with the best in the world. Tomorrow I have to convince myself I can make the final."
Fraser was the third-fastest qualifier behind her compatriots Kerron Stewart and Sherone Simpson.
It was a good night for Jamaican athletes with Markino Buckley and Danny MacFarlane reaching the men's 400m hurdles final.
But they will face the in-form American trio of Angelo Taylor, Bershawn Jackson and Kerron Clement who were the three fastest qualifiers.
British pair Marilyn Okoro and Jenny Meadows failed to advance to the final of the 800m after finishing sixth in their respective semi-finals.
Okoro clocked a time of one minute 59.53 seconds and Meadows was 0.10secs quicker despite being involved in some pushing at the bell which saw Sviatlana Usovich of Belarus almost sent crashing to the track.
"I should have made the final," Okoro said. "I just didn't stick to my race plan and got pushed about a bit.
"It is another one for the memory bank. I'm not going to say I'm happy to make the semis but I can learn from it."
Well-fancied Kenyan duo Pamela Jelimo and Janeth Jepkosgei both won their semi-finals while Mozambique veteran Maria Mutola produced a late sprint to qualify for her fifth Olympic final.
World champion Ohuruogu comfortably won her heat in 51 seconds flat to progress to Sunday's 400m semi-finals while world silver medallist Sanders looked in good shape as she clocked 51.51, while McConnell ran 51.87.
The main threat to Britain's medal hopes in the 400m is expected to be American Sanya Richards, who also qualified with ease.
Sanders told BBC Sport: "I always get more nervous for the first round. You don't know where you're at and where your competitors are at.
"It's nice to get it out of the way and focus on tomorrow night."
Pole vaulter Kate Dennison failed to reach the final despite a personal best of 4.40m, while world record holder Elena Isinbaeva needed just one attempt at 4.60m to qualify automatically.
Andrew Lemoncello failed to progress in the 3,000m steeplechase, finishing ninth in his heat after a time 13 seconds below his personal best.
Yakob Jarso of Ethiopa, France's Mahiedine Mekhissi and American Anthony Famiglietti progressed from Lemoncello's heat, while Bouabdellah Tahri, Brimin Kiprop Kipruto, Ruben Ramolefi and Richard Kipkemboi Mateelong were among the other qualifiers.