The Latest from the world championships (all times local):
12:05 p.m.
Abdullah Al-Qwabani came to the Bird's Nest to take on the best in the world, and did it in bare feet.
The 16-year-old Yemeni ran 12 1/2 laps on the synthetic track without shoes and recorded a personal best time of 16 minutes, 2.55 seconds. He was a distant last among the 39 runners who finished in the two heats of the 5,000 meters at the world championships.
But he did get to rub shoulders with some of the biggest names of the event, racing in the same heat as Olympic 5,000- and 10,000-meter champion Mo Farah, who was second-fastest of all those advancing in 13:19.44.
11:40 a.m.
American hurdler Ronnie Ash disputed his disqualification in the second heat of the 110-meter hurdles at the world championships on Wednesday, and lingered behind for several minutes after being ordered to leave the track.
Ash appeared to move when the field was set in the blocks and the red flag was waved. He stayed in his lane until officials confirmed he had to leave.
When he did leave to the rear of the start area, he was stopped by ushers who refused to let him back in the tunnel under the stadium, further delaying his exit.
Czech hurdler Petr Svoboda was disqualified for a false start when the field was re-set, meaning lanes three and six were empty when the heat eventually started.
Pascal Martinot-Lagarde won the heat in 13.35 seconds.
11:25 a.m.
With a late kick and a lunge, Caster Semenya ensured an automatic qualifying spot in the next round of the 800 meters when she finished third in her opening heat at the world championships on Wednesday.
The 2009 world champion and 2012 Olympic silver medalist was running in seventh place rounding into the last straight and surged to finish in 1 minute, 59.59 seconds, just behind Marina Arzamosova of Belarus and Linsey Sharp of Britain in the fastest of the six heats.
Defending champion Eunice Sum of Kenya also qualified automatically, winning her heat in 1:59.67.
10:20 a.m.
Mo Farah stumbled a couple of times on the track Wednesday as he started the second stage of his bid for a long-distance double at the world championships.
Farah, who won the 5,000- and 10,000-meter gold medals at the 2012 London Olympics and has already won the 10,000 title in Beijing, stumbled halfway through his opening heat of the 5,000 and again tripped in a tight pack about 150 meters from the finish. He recovered his footing quickly to cross in second place in his heat to advance in 13 minutes, 19.44 seconds.
9:40 a.m.
Usain Bolt will be back in action in the semifinals of the 200 meters on Day 5 of the world championships, which got underway with the first round of the 5,000 meters and qualification in the women's hammer throw.
Triple jump for the men and the women's 800 will follow in a morning session that concludes with the first round in the 110-meter hurdles.
There are five finals on the program Wednesday, with the men's javelin and the 400 and women's pole vault, 400-meter hurdles and steeplechase.