Caster Semenya put the "nonsense" of IAAF rules on women's testosterone behind her to storm to 1500m victory at the opening Diamond League meet of the season on Friday, American sprinter Noah Lyles and Qatari high jumper Mutaz Barshim also dominating their events.
"I don't talk about nonsense," Semenya, the double Olympic 800m gold medallist, angrily rebutted when asked about why she never commented on the regulations to counteract hyperandrogenism, the medical condition which causes women to produce high levels of male sex hormones.
IAAF president Sebastian Coe had earlier hit a defiant note amid criticism of the new rules, insisting they were "appropriate for the sport".
The issue is controversial because it pits principles of fair competition against the rights of women born with the condition. Athletes such as Semenya will only be able to compete when the rules come into effect on November 1 if they take medication to reduce their levels of male sex hormones.
Semenya showed her 800-1500m double at the Commonwealth Games had set her up for a fiery start to the season.
In front of a near-capacity 15,000 crowd at the Qatar Sports Club, buoyed by dancing, chanting banks of partisan Kenyan and Ethiopian expatriates, Semenya sat in sixth of a loaded 15-strong field through the first lap in temperatures of 30 degrees Celsius (86F).
The South African made her move with 200 metres to run, gliding effortlessly up on Nelly Jepkosgei's shoulder and going past with apparent ease to win in a personal best and national record of 3min 59.92sec.
"The most important thing was to break the magic four minutes, and obviously we did that," said Semenya.
American Lyles, 20, stormed to an impressive victory in the men's 200m in a personal best of 19.83sec, Trinidad and Tobago's Jereem Richards also going sub-20 to push reigning world champion Ramil Guliyev of Turkey into third.
Canada's Andre De Grasse, returning to competition after an injury that ruled him out of last year's worlds, could only finish sixth (20.46).
"Right now, I hope my performance stays the same!" said Lyles.
De Grasse added: "I started a bit rusty but I'll just take it from there and improve for the rest of the season."
- Ta Lou trumps Thompson -
Marie-Josee Ta Lou of the Ivory Coast won a star-studded women's 100m, the 2017 world double sprint silver medallist clocking a personal best of 10.85sec, Nigerian Blessing Okagbare-Ighoteguonor taking second in 10.90sec.
"I don't want to say I want to win everything this year, but if I get to beat my personal best again like today, then that would be fantastic," Ta Lou said.
Reigning Olympic champion Elaine Thompson of Jamaica had to be happy with rounding out the podium, while current 200m world champion and Olympic silver medallist Dafne Schippers of the Netherlands came in sixth.
There was double home delight, timely given Doha will host next year's World Athletics Championships.
World champion Barshim, undefeated last season, went clear at 2.40m to set himself up nicely for another assault on the long-standing world record of 2.45m set by Cuba's Javier Sotomayor in 1993.
Barshim's win was preceded by Saudi-born teammate Abderrahman Samba's stunning victory in the 400m hurdles in 47.57sec, a personal best that was also an Asian and Diamond League record.
"Winning at home is an amazing feeling, especially to break all those records," Samba said, warning: "I have a feeling this will be a great season for me and all I want to do is run faster."
Reigning world, Olympic and European champion Sandra Perkovic thrived in the warm conditions, the Croat launching the discus out to a Diamond League and meet record of 71.38m on her third attempt.
Steven Gardener of the Bahamas also tore up the men's 400m, clocking an outstanding personal best of 43.87sec, a national and meeting record.
Cuban Pedro Pablo Pichardo got one over on arch-rival Christian Taylor with victory in the triple jump with a best of 17.95m, but American hopes were restored when Sandi Morris (4.84m) beat Greece's reigning world, Olympic and European champion back into fourth in the pole vault.
Thomas Rohler led a German podium clean sweep in the javelin, his 91.78m not quite reaching his stellar effort of 93.20m, the second furthest ever, two years ago.