Paris - Caster Semenya put her run-in with the IAAF over controversial new rules on testosterone firmly to one side as she scorched to the fourth-fastest time ever run in the women's 800m at Saturday's Diamond League meet in Paris.
There was also an outstanding performance by Qatar's Abderrahman Samba, who set the second-fastest time ever in the men's 400m hurdles in balmy conditions of 29 degrees Celsius at the Charlety stadium in southern Paris.
Semenya, double Olympic champion (2012, 2016) and twice world champion (2009, 2017), completely dominated her two-lap sortie, leading from gun to tape to clock a scintillating 1:54.25 that left the large crowd gasping.
Only Kenyan Pamela Jelimo, in Zurich in 2008, Soviet Union's Nadezhda Olizarenko in 1980 and Czech world record holder Jarmila Kratochvilova (1:53.28), in 1983, have gone faster.
Semenya was initially tracked by Burundi's Olympic silver medallist and reigning world champ Francine Niyonsaba and American Ajee Wilson.
The 27-year-old South African hit the bell in a swift 56.12, gradually pulling away down the back straight before turning the screw from 200m and not letting up through to the line, maintaining her unbeaten form over the 800m since her elimination in the semi-finals of the 2015 worlds in Beijing.
It was the perfect tonic for Semenya, who, off the track, has turned to the Court of Arbitration for Sport (CAS) in her challenge of IAAF rules on testosterone occurring in female athletes that are to be introduced on November 1.
Naturalised Qatari Samba carried on his remarkable start to the season, scorching to the second fastest time ever over the gruelling event.
His 46.98 winning time edged him ever closer to the world record of American Kevin Young set back in 1992. It also beat the season's best of 47.02 set by Antigua's Rai Benjamin, who opted to run the 200m in Paris.
"I've said it before - I want to become the fastest man in the world and I work hard to achieve it," said Samba, who has only been doing the event for two years, but has now added Paris to his list of Diamond League victories that already include Doha, Rome, Oslo and Stockholm this season.
"It feels great to be the second fastest man in history. The world record is getting close but I just want to improve step by step and run fast. I've improved my technique since last year and who knows, maybe I can be one second faster next year!"
Samba's 20-year-old rival Benjamin clocked a personal best of 19.99 in the 200m behind American world indoor 400m record holder Michael Norman, his training partner, also 20, who clocked an admirable 19.84 after two false starts.
Ronnie Baker wrapped up the sprints for the US team, timing a personal best of 9.88 as France's Jimmy Vicaut, China's Su Bingtian and South African Akani Simbine all went sub-10.
Sergey Shubenkov, the current world champion from Russia and the only athlete to have run a sub-13 time this year, was harshly ruled to have false started in the 110m hurdles, Jamaican Ronald Levy going on to win in 13.18.
"Obviously I did not false start, but the system said I did," the Russian said, his words seemingly backed up by video repeats.
There was no such drama, however, for reigning Olympic champions Sandra Perkovic of Croatia and Colombian Caterine Ibarguen, who claimed victories in the women's discus (with a meet record of 68.60m) and triple jump (14.83m) respectively.
44 for Lasitskene
The women's high jump saw Russia's defending double world champion Mariya Lasitskene seal an incredible 44th consecutive victory with a season's best of 2.04m, going very close at 2.08.
Belgium's Nafissatou Thiam, the Olympic and world heptathlon gold medallist, was second with 2.00m.
Renaud Lavillenie's hopes of pleasing the home crowd fell flat after the world record holder could only finish third in a pole vault competition won by American Sam Hendricks with 5.90m on count-back from 18-year-old Swede Armand Duplantis in second.
Lavillenie's team-mate Kevin Mayer won a four-man triathlon comprising a long jump, shot put and 110m hurdles, but there were tears for sprinter Christophe Lemaitre, who pulled up injured in his bid to make the 10.15 qualifying time to compete in the 100m in August's European championships in Berlin.
Commanding, unstoppable, dominant. Words struggle to describe @caster800m ???? this season as she lowers her own WL to 1:54.25 DLR, MR, NR, PB!#ParisDL #DiamondLeague #RoadToTheFinal pic.twitter.com/phNsu3QnAV— IAAF Diamond League (@Diamond_League) June 30, 2018