(Reuters) - South African Caster Semenya romped to the fourth-fastest women's 800 metres ever and Qatari Abderrahman Samba produced the second-best 400 metres hurdles of all time in a sparkling Paris Diamond League meeting on Saturday.
Olympic and world champion Semenya cruised home in a lifetime best 1:54.25 and the dominant Samba clocked 46.98 seconds for his fifth consecutive Diamond League win.
Semenya, whose middle-distance running career could be under threat because of a new IAAF hyperandrogenism rule that she is challenging, took nearly a second off her personal best as she claimed her 25th consecutive final win in the event. Burundi's Francine Niyonsaba was second in 1:55.86.
"I did not expect that," Semenya, who ran without pacemakers, told reporters. "I was thinking 1:54.99 could be possible but this was great."
The IAAF rule, against which Semenya has appealed to the Court of Arbitration for Sport (CAS), would effectively give her a choice of taking medication to restrict her testosterone level or move to longer-distance events. It is scheduled to become effective in November unless overturned by CAS.
"I am just a human and if you want to be an inspiration to the world and to the youth, you cannot focus on negative things," Semenya said.
Only Czech world record holder Jarmila Kratochvilova (1:53.28), Ukrainian Nadezhda Olizarenko (1:53.43) and Kenyan Pamela Jelimo (1:54.01) have run faster than the South African.
Samba became just the second runner to break 47 seconds in the 400m hurdles. The other was American world record holder Kevin Young, whose 46.78 won the 1992 Olympics.
"I made a small mistake at the start, lost my balance on the first hurdle so I did not expect to run so fast," said the 22-year-old, whose previous best was 47.41.
Russian world champion Mariya Lasitskene also continued her dominance, winning her 45th consecutive high-jump competition with a sparkling season's best of 2.04 metres.
(Reporting by Gene Cherry in Raleigh, North Carolina; Editing by Neville Dalton)