Usain Bolt and fierce rival Justin Gatlin eased into the 200 metres semi-finals as middle distance greats David Rudisha and Genzebe Dibaba blazed to gold at the world athletics championships in Beijing.
Bolt, the biggest name in athletics, returned to the Beijing track two days after pipping Gatlin to retain his world 100m title, and won his 200m heat in an easy 20.28 seconds. Gatlin topped his heat in 20.19.
Sweat dripping from his beard on a humid evening, Bolt then icily shrugged off the threat of two-time doping offender Gatlin in his favourite event.
"It actually means more to me than the 100m," said the world record holder, who recovered from pelvic trouble just in time to deliver positive headlines after allegations of widespread doping engulfed the sport.
"I'm feeling tired and my legs are sore - just from the fact it was an up and down season. Hopefully I can get my technique right and give it my best in the final," added Bolt, who returns to the Bird's Nest for today's semis, with the final scheduled for Thursday.
Rudisha stormed to a second world title in the men's 800 metres, meanwhile, after running a typically masterful race in sapping conditions, taking Kenya to the top of the gold medal standings with four after Nicholas Bett's earlier victory in the 400m hurdles.
Hot favourite Dibaba oozed class as she won the women's 1500m title with another sumptuous performance, the Ethiopian finishing strongly in 4:08.09 under the floodlights at a packed Bird's Nest stadium.
Long jumper Greg Rutherford won a third gold medal for Britain on day four of the competition, launching himself to a season's best of 8.41 metres to add a world title to his Olympic, European and Commonwealth crowns.
Australian Fabrice Lapierre took silver with 8.24m, as home favourite Wang Jianan claimed bronze after leaping 8.18 to bring the house down in Beijing.
There was a first gold medal for Cuba as Denia Caballero won the women's discus, while on the track and somewhat overshadowed by the Usain Bolt show, American Allyson Felix qualified quickest for Thursday's women's 400m final in a season's best of 49.89.