The 27-year-old from Oslo won a bunch sprint, after a high-tempo stage, at 187.5km the longest of the race, from Al Wakra to Al Khor Corniche.
After holding off Italian Andrea Guardini of Astana and BMC rider Greg Van Avermaet of Belgium he said:
“It was really tough with the wind and there was practically a sand storm.
“Sand was going in my mouth, everywhere and it was one of the most difficult days I’ve ever had.”
“Everyone was tired, including myself but I thought that I was one of the favourites in that small group at the end and I know I’m fast.” he added.
The victory for Kristoff, who won two stages on last year’s Tour de France, gave him a one second lead over Belgian veteran Tom Boonen (Quick Step), in the overall standings, while Van Avermaet is three seconds adrift.
The peloton were pushed along by a fierce tailwind that saw them cover a distance of 50km longer than Sunday’s stage in almost exactly the same time.
Two casualties of the tough conditions were British 2012 Tour de France champion Bradley Wiggins and German star Marcel Kittel who arrived home 9min 18sec behind the leaders.
Tuesday will feature a 10.9km individual time-trial around the Lusail Circuit as the race follows a six stage route which finishes in Doha on Friday. – Agence France-Presse