Morocco's 21-year-old rising star Soufiane El Bakkali saw off Kenyan rival Jairus Kipchoge Birech in the men's 3,000m steeplechase in a personal best of 8min 05.12sec.
Semenya boasts the fastest two-lap time this season with the 1:56.61 she ran at the Doha Diamond League in May.
Nijel Amos of Botswana crossed the line first with a time of 1:43.91, Kenya's Kipyeogon Bett was second in 1:44.28, and Donavan Brazier placed third at 1:44.62.
The Brit clocked 20.22 as American Trials victor Fred Kerley was fourth in 20.27.
Botswana's Nijel Amos, who has recovered from injuries to hit top form in the last month with Diamond League 800m victories in Paris and London, maintained his pre-eminence as he won in 1:43.91 in front of Kenya's Kipyegon Bett, who clocked 1:44.28, and Donovan Brazier of the U.S., who clocked 1:44.62.
American Ryan Crouser won with a throw of 22.47 metres.
Andriy Protsenko of Ukraine was the only man to clear 2.29m in the high jump, and followed up with three unsuccessful attempts at 2.33.
Samsung Pay adds PayPal option
For offline payments, they can swipe up from the bottom of their phone screens to select either a registered card or PayPal. Now consumers will be able to make payments easily on Samsung's budget and mid-range phones.
Amazon Trademark Filing Puts Target On Blue Apron, Meal Delivery
Amazon has had its humbling stumbles - like Fire Phone, Amazon Auctions, and $399 Kindle - but those are rare. Blue Apron isn't the only company in this market, but it was establishing itself as the top brand.
India, Pakistan Army exchange heavy fire along LoC in Rajouri
In May India accused Pakistani forces of killing two soldiers patrolling the LoC and mutilating their bodies. The girl has been identified as Sajida Kousar.
South Africans did have something to celebrate in the Moroccan capital after Rushwal Samaai (8.35m) edged out the competition in the men's long jump, just ahead of Jarrion Lawson (8.33) and Yahya Berrabah (8.14). Roto looked off balance out of the blocks and battled to get the ascendancy, with Great Britain's Ujah Chijindu winning the race in a time of 9.98.
Semenya hasn't run an 800m since mid-June and will do so again at the next Diamond League meet in Monaco on Friday night‚ the last before the world championships in London next month.
The 33-year-old Colombian won with 14.51m, 20cm ahead of Kimberly Williams of Jamaica, with Greece's Paraskevi Papachristou taking third place with 14.21, a centimetre ahead of London 2012 champion Olga Rypakova of Kazakhstan.
Okagbare-Ighoteguonor who holds the Nigerian record in the event (10.79 seconds) failed to build on her impressive 10.99 seconds run in London last week but however moved up to fourth in the qualification standings for the Diamond League final with 17 points after conclusion of five of six 100m qualification meetings.
Ivory Coast's Ben Youssef Meite was second (10:01), with fellow Briton Nethaneel Mitchell Blake (10:18) in third place.
Hughes set a season's best 20.22s to finish behind Andre De Grasse of Canada and USA's Ameer Webb, while Eilidh Doyle also came third in the women's 400m hurdles with a time of 54.92 - the race being won by Zuzana Hejnova of the Czech Republic.