The Spaniard birdied his first three holes on Thursday and had nine in total for an eight-under 64.

The world's 122nd-ranked player dropped only one shot, on the par-4 5th hole as the temperature pushed toward the mid-30°s C at Doha Golf Club.

"The temperature this morning was nice but now it's boiling," Larrazabal said.

"It's probably 35 or 36 degrees right now. So I keep drinking a lot of water and keep making birdies."

Shubhankar Sharma, Marcus Helligkilde, Romain Langasque and Adrian Meronk were all two shots behind in a tie for second, with France's defending champion Antoine Rozner (68) four shots off the lead.

Alongside Rozner in joint-eighth place was Wayne Ormsby, whose own five-birdie round of 68 put him top among the Australian contingent.

Jason Scrivener had three birdies and three bogeys in his level-par 72 but Queensland's European Tour regulars Scott Hend and Maverick Antcliff suffered poor days, shooting five-over 77s.