Usain Bolt and Justin Gatlin are set for another showdown in the 200 metres final after clocking the fastest times in the semi-finals at the world athletics championships in Beijing.
Bolt, who beat Gatlin when they met for the first time this year in the 100 metres final, looked relaxed and took time to chat with a fellow competitor as he approached the line to win his heat with his first sub-20 second time of the year.
The 29-year-old Jamaican, unbeaten in his favourite event at a major championship since the 2008 Beijing Olympics, said he still had something left in the tank for tonight's final after clocking 19.95 seconds, while Gatlin's time was 19.87, though Bolt said he ran maybe 90 percent.
Kenya have won their first ever World Championship gold medal in a field event with an unlikely triumph in the men's javelin.
The victory, mixed with another steeplechase gold and two positive drug tests, made for an eventful day for the African nation in Beijing.
Julius Yego claimed gold in the men's javelin with a massive effort of 92.72m - the third-biggest throw of all time and the longest since Czech legend Jan Zelezny threw 92.80m back in 2001.
The steeplechase is a much more predictable source of track and field medals for the east African powerhouse and Hyvin Jepkemoi delivered again in the women's event.
But Kenyan team-mates Joyce Zakary and Koki Manunga failed pre-competition drug tests and were provisionally suspended.
Track and field's world governing body said the pair had been tested at the athletes' hotel before their competition started as part of "targeted tests".
Zakary bettered the 400m national record with 50.71 in the heats earlier this week.
Manunga flopped in the opening round of the women's 400m hurdles.
"Athletics Kenya has already met with the IAAF and the athletes involved, and has begun investigating the situation which led to these results and appropriate follow-up action will be taken in Kenya," track and field's governing body in the east African running powerhouse added in a statement."
Yego said the positive tests were a shame for Kenyan athletics.
"In sport you win clean so it's a shame for them. I can't make any more comment on that," he said."
South African Wayde van Niekerk announced himself as the next big thing in 400m running with a commanding victory in 43.48 seconds - making him the fastest non-American athlete ever over the distance.
Left in his wake was 2009 world champ LaShawn Merritt from the US - whose silver medal time of 43.65 was a PB - and Grenada's reigning Olympic champion Kirani James.
The other gold medals decided went to Cuba's Yarisley Silva in the women's pole vault and Zuzana Hejnova from the Czech Republic in the women's 400m hurdles.