Doha, Sep 28 (AFP) Kenya's Ruth Chepngetich powered through brutal heat and humidity to win gold in the women's marathon on Saturday, bringing the curtain down on a dramatic opening day at the World Athletics Championships in Doha.

With around two dozen runners in the 68-strong marathon field falling by the wayside as the sweltering conditions took their toll, Chepngetich dug deep to win the first gold medal of the championships in a time of 2 hours 32 minutes and 43 seconds.

The marathon, held on a floodlit course alongside Doha's waterfront Corniche, had started at 11.59 pm local time on Friday, in a scheduling move designed to protect athletes from the furnace-like daytime heat.

But even allowing for the near-midnight start, temperatures of around 32 degrees Celsius (90 degrees Fahrenheit) and humidity approaching 80 percent proved too much for several exhausted competitors who were seen being stretchered away or escorted from the course in wheelchairs.

Race organisers had staffed the course with extra medical personnel and an increased number of watering stations to help athletes stay hydrated.

Chepngetich, 25, took the tape shortly after 2.30 am local time, pulling clear after kicking for home on the final lap, crossing the finish line over a minute clear of her nearest rival, defending champion Rose Chelimo of Bahrain. Namibia's Commonwealth Games champion Helalia Johannes claimed bronze.

- 'Too hot' -

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"It was too hot," said a weary Chelimo, who said seeing so many competitors wilt had "strengthened my resolve."

The high number of dropouts however is likely to renew debate about safety for marathon runners and endurance athletes competing in Doha.

France's world champion race walker Yohann Diniz earlier Friday lashed out at the decision to make runners and walkers compete in the heat rather than the climate-controlled Khalifa Stadium, where the bulk of events are taking place.

"I am disgusted by the conditions," the 41-year-old world record holder said.

"They take us for idiots. If we were in the stadium we would have normal conditions, between 24-25 degrees, but outside they have placed us in a furnace, which is just not possible."

In the opening track events on Friday, the biggest roar of the night was reserved for two unheralded long distance runners Braima Suncar Dabo of Guinea-Bissau and Jonathan Busby of Aruba.

Dabo and Busby had already been lapped and were the only men left on the track at the end of their 5,000m heat, with the rest of the field having finished several minutes earlier.

- Helping hand -

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Busby, 33, had slowed to almost a crawl down the back straight on the last lap, lurching forward uncertainly and appearing close to collapse.

It was then that Guinea Bissau's Dabo came to the rescue, stopping to prop up his fellow racer and leading him around the final 200 metres to the finish line.

It was a scene that was reminiscent of Derek Redmond's famous hobbling finish at the 1992 Olympics, when the British 400m runner was helped over the line by his father after breaking down.

With the crowd roaring them over the line, Busby collapsed and was eventually led away in a wheelchair.

"I just wanted to help the guy finish the race," Dabo, 26, said afterwards through a translator.

"I wanted to help him cross the line. I think anyone in that situation would have done the same thing," added Dabo, a student based in Portugal.

In the 100m, meanwhile, US sprinter Christian Coleman laid down an emphatic marker with an easy win in his opening heat. Coleman, the favourite for gold in Saturday's final, shrugged off a drugs controversy to clock 9.98sec.

The 23-year-old American was the only man to duck under 10 seconds, and looked to have plenty left in the tank as he crossed the line.

Coleman was only cleared to compete in Doha earlier this month after an anti-doping case against him which could have led to a long ban was withdrawn on a technicality.

A tight-lipped Coleman later brushed past journalists following his heat, refusing to take questions and muttering only a cursory "Felt great." AFP KHS

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