Brussels - US sprinter Noah Lyles will target world gold next month after "clenching" his way to a "chaotic" 200m victory in 19.74 seconds in the Brussels Diamond League final on Friday.
The performance capped a remarkable end of the elite 14-meet track and field circuit for the 22-year-old, who last week pipped American teammate and current world champion Justin Gatlin to win the 100m trophy.
The American went into the 200m in the Belgian capital as hot favourite, but revealed he had to race despite a last-minute need for the toilet.
The track at Brussels' King Baudouin stadium is a rapid one, but Lyles said the renowned fast bend all went over his head and he concentrated on getting through the finish line and a toilet.
"A lot happened in that race! I get on the line and as soon as the starter says get to the blocks, it started raining. Then my bib comes off and then I had to use the bathroom and that's when the race became a lot more complicated," he said.
"I didn't get to experience the Brussels bend as I wanted to. It was more me clenching, trying to run and then using the bathroom."
Lyles acknowledged that it was a "cool achievement to have two trophies".
"But it's a little achievement, my main goal is to run faster than my last time each time.
"I've got the 100, now the 200m, so now it's the world championships."
Michael Norman claimed a degree of revenge over compatriot Fred Kerley, who beat him to the US title in Des Moines, winning the 400m in 44.26sec. Kerley came in second at 0.20sec.
Norman's 43.45sec in April made him the joint fourth fastest over the one-lap race: only South Africa's injured reigning Olympic and double world champion Wayde van Niekerk and the retired American duo of Michael Johnson and Butch Reynolds have gone faster, with Jeremy Wariner having matched his time.
Like Lyles, Norman plumped for a wider lane, in his case five, to make the most of the racer-friendly bend, and in fresh conditions held his nerve with Kerley hitting the final 80 metres in front.
With the world champs having been pushed back because of fears over the oppressive weather in the Qatari capital, this year is the first in which the Diamond League has concluded ahead of a major global championships.
Winners claimed $50,000, a Diamond trophy and a wild card entry for the Doha worlds. Importantly, the finals were loaded as athletes saw them as an ideal opportunity to fire out a warning shot or two ahead of Doha.
Britain's European champion Dina Asher-Smith did just that in the women's 100m, clocking a season's best of 10.88sec to edge out former world and Olympic champion Shelly-Ann Fraser-Pryce of Jamaica.
"Don't call me favourite for the worlds," said Asher-Smith.
"Tonight was like British weather and I just took my chance."
Elsewhere, Ethiopian Getnet Wale upset Moroccan Soufiane El Bakkali to win the 3000m steeplechase, while Ethiopian-born Dutch runner Sifan Hassan snatched the women's 5000m trophy, Kenya's world champion Hellen Obiri in fourth.
Obiri's teammate Timothy Cheruiyot produced another dominant display to win the men's 1500m in 3:30.22 for a third consecutive Diamond trophy, and one week after compatriot Donavan Brazier won the men's event in Zurich, American Ajee Wilson racked up a gun-to-tape victory in the women's 800m in 2:00.24.
Christian Taylor matched French pole vaulter Renaud Lavillenie's record tally of seven Diamond trophies when he went out to 17.85m to beat long-time rival Will Claye in the triple jump.
Croatia's Sandra Perkovic and Colombia's Caterine Ibarguen both missed their chance to match Taylor, the former finishing second to Cuban Yaime Perez in the shot put while the latter finished eighth in a long jump competition won comfortably by Germany's Malaika Mihambo.