The 23-year-old on Saturday took gold with a time of 2:32:43, the slowest time to ever win the championships in a race that saw nearly a third of the 70 starters – 28 out of 68 – fail to reach the finish line.
Defending world champion Rose Chelimo, 39, settled for silver crossing the line more than a minute later with a time of 2:33.46.
Commonwealth champion, Namibia’s Helalia Johannes, also 39, took bronze clocking a time of 2:34.15.
The opening day of the 10-day event began with the governing International Association of Athletics Federations (IAAF) issuing a statement that the marathon would go ahead despite concerns over extreme heat and athlete welfare.
As temperatures hovered in the mid-30s degrees Celsius (mid-90s degrees Fahrenheit), the runners waited their turn in the spotlight as the Emir of Qatar Sheikh Tamim bin Hamad Al Thani, with International Olympic Committee (IOC) President Thomas Bach sitting on one side and IAAF boss Sebastian Coe on the other, declared the championships open to an explosion of fireworks.
With the first gold medal of the championships up for grabs, the women stepped up to the start line ready to tackle a steamy 42.195 kilometres (26.2 miles) floodlit course along the waterfront of Doha’s famous Corniche promenade.
The race scheduled to begin one minute before midnight on Friday and finish in the early hours of Saturday saw the field head out right on the stroke of 12.
The midnight start tempered the sting of a searing sun but with the temperature sitting at 32.7C (90.86F) and the humidity index at 73 percent the conditions were right on the limit of what the IAAF said was allowable.
“I am very happy with the win and bringing back the gold to Kenya,” Chepngetich said.
“It was a tough race but I knew what to expect as I ran in Dubai. I trained for this weather running in the afternoon when the sun was high,” she added.
Some of the athletes felt the conditions were so severe that the race should not have been run.
“The humidity kills you. There is nothing to breathe. I thought I wouldn’t finish,” said Volha Mazuronak of Belarus.
“It’s disrespect towards the athletes. A bunch of high-ranked officials gathered and decided that it would take [the championships] here but they are sitting in the cool and they are probably sleeping right now,” she added.