Mo Farah secures Britain's first gold by winning the 10,000m
Ennis-Hill in first place and Johnson-Thompson second after four heptathlon events
Justin Gatlin (9.83 secs) and Usain Bolt (9.97) in 100m heats
Ujah, who last competed at the London Anniversary Games in July, is content with his performance.
"I wanted to come here and get the first round done and move on to tomorrow," he says. "When you're ready, you're ready, so it's kind of tough to wait, but you've got to wait for the right day and tomorrow I'll bring that. I've got to sharpen up tomorrow, it looks good."
British champion CJ Ujah is in the blocks for the next 100m heat. Only six starters in this race, which makes it a bit easier to qualify, and Ujah burst through in second spot, trailing Trayvon Bromell (9.91). The Briton (10.05) safely through to the semifinals.
Michael Johnson
BBC Sport athletics expert & 400m world record holder
"Richard Kilty's a 60m runner. It's all power and technique. He needs to work on speed, and on his speed endurance. He's got to hold that speed."
Image source, Getty Images
Steve Cram
BBC athletics commentator
"It's what we've come to expect from Richard Kilty. He hasn't raced very much. He's always going to get out well. He can get a bit ragged and starts to tighten, and the guys come past him."
"It was alright," says Kilty to BBC Sport. "I got out pretty well. It's my first race back in a long time. Hopefully, I can get one of the fastest losers spots. It wasn't a great run from me, but I'm just a bit rusty at the moment."
Stockton's finest, Richard Kilty, is in action in the third men's 100m. The Briton starting from lane two and is out of the traps brilliantly. He's overrun in the final half of the race, though, and the world indoor champion does not qualify automatically but his fourth-place finish (10.12 secs) could be enough.
The race was won by Qatar's Femi Ogunode in 9.99 seconds.
We've got time before the third heat starts to tell you Jessica Ennis-Hill leads the heptathlon after three events. Katarina Johnson-Thompson achieved a personal best in the shot, but drops from second to ninth overall.
Tyson Gay probably the most recognisable face in the second men's 100m heat. A false start for South Africa's Anaso Jobodwana so he leaves the track and we attempt to go again.
A swig of water for Gay... he closes his eyes, reaches skywards before the starter's bang goes off.
Gay overtakes Nickel Ashmeade (10.19) around 50m, clocking 10.11 seconds to win. The Jamaican was second, with Christophe Lemaitre (10.24) also through in third.
The fires are being stoked today ahead of Sunday night's men's 100m final. For thegood versus baddash gold-medal showdown to unfold both Usain Bolt and Justin Gatlin must progress from their heats, which they should do so comfortably, of course. Gatlin is in the sixth heat, Bolt the seventh.
We'll also be keeping an eye on Britons CJ Ujah (heat 4), Richard Kilty (heat three) and James Dasaolu (heat six). Actually, we'll be keeping an eye on everyone.
You can access our day-by-day championship guidevia this link.
Image source, BBC SportMichael Johnson
BBC Sport athletics expert & 400m world record holder
"That was a display of great technique and real relaxation from Asafa Powell. He's out to prove something after the drugs ban."
Colin Jackson
Two-time world 110m hurdles champion
"I spoke to Asafa Powell earlier this week, and he said he wanted to go under 10 seconds as often as he can at this championships. At 9.96 we have to take him at his word."
Asafa Powell, in lane one, enjoys a fine start and eases up once he realises he's on course to win, doing so in 9.95 seconds. The Jamaican looked relaxed. "A sauntering Powell," says Steve Cram in the commentary box.
Image source, Getty ImagesWhat's next on the track? Asafa Powell is on the start blocks which must mean it's time for the men's 100m heats. On your marks...
Katarina Johnson-Thompson gets over 12m on her third attempt, but 12.07m is below the personal best 12.47m she threw in the first round. The Briton's facial expressions not giving much away as she returns to the bench.
A sharp intake of break from Jessica Ennis-Hill as she prepares for her final attempt in the shot. The Olympic champion smiles as she walks away from the circle, but she probably would have wanted to throw further than 13.41m. Her second throw - 13.73 - her best.
Image source, PAMichael Johnson
BBC Sport athletics expert & 400m world record holder
Quote MessageBershawn Jackson will be scratching his head. He'll be very disappointed. His big problem was the last hurdle. He came off it so off-balance, in just the most ridiculous position you could possibly imagine.
What does former 400m hurdles world champion Dai Greene think after the heats? Well...
Colin Jackson
Two-time world 110m hurdles champion
"As a commentator, I should not be speechless, but I am with Bershawn Jackson's performance. With a season's best of 48.09 seconds, you expect him to be able to control this race. But he always has a tendency to fall asleep at the magical 300m mark. When you've got fatigue in your legs, those barriers can seem pretty high. He almost climbed over them. When you do that and hit the ground, your speed goes from something reasonable to zero. That's exactly what happened."
Katarina Johnson-Thompson, with a personal best already in the bag, fails to improve on her first effort, throwing 12.30m with her second attempt in the shot.
Jessica Ennis-Hill is sitting on the sidelines, looking into the middle distance...
Image source, ReutersFormer world champion Bershawn Jackson is the in-form athletes of the season in the men's 400m hurdles, but American messes up the fourth heat.
Stuttering into the final barrier, the fastest 400m hurdler of the year fails to qualify! "He'll be scratching his head," says Colin Jackson.