Frustration followed for the 29-year-old Spanish Open runner-up as torrential rain forced play to be suspended at the Diamond Country Club, with Austria's Hamza Amin, a former Pakistan amateur champion who only turned pro last year, in second place with three birdies in his first seven holes.
Swedish trio Steven Jeppesen, Ricard Karlberg and Niclas Fasth, with Italy's Alessandro Tadini, were a shot further back, with Wales' Stephen Dodd and England's Andrew Marshall another one adrift.
Larrazabal, a former BMW International Open winner, started with a birdie on his opening hole - the 10th - then eagled the par-five 13th, and gained further shots at the 14th, 16th and 18th to reach the turn in a six-under-par 30.
Former tennis world number one Yevgeny Kafelnikov was making his second European Tour appearance - following his debut four years ago when he missed the cut by 27 shots in the Russian Open.
But the 38-year-old former winner of the French and Australian Opens was a more creditable three over after 14 holes when the rain halted proceedings, with play due to re-start at 3.20pm local time.