Larrazabal’s round included four birdies and an eagle through the first 12 holes before stormy weather and rain delayed play for three hours and 40 minutes.
The Spaniard, who played the second nine holes first, opened with a birdie before an eagle at the 13th, as well as birdies on 16 and 18 before the break.
Larrazabal went on to record back-to-back birdies at the sixth and seventh, after play resumed, to finish on 8-under-par for the day.
Play was suspended for the day because of darkness with Denmark’s Thorbjorn Olesen one shot adrift at 7-under after 14 holes.
Frenchman Thomas Levet and Wil Besseling of the Netherlands were another shot back at 6-under after 14 and 13 holes respectively.
Anthony Wall was fifth on 5-under after 13 holes while Scotland’s Alistair Forsyth and England’s Oliver Wilson, who were two of just 74 players to complete their round, were tied for sixth after rounds of 68. They were joined by Emiliano Grillo and Felipe Aguilar through 13 and 12 holes respectively.