The Challenge Tour graduate, fresh from his first top five finish on the European Tour at the Austrian Open, made five birdies and an eagle at the long third to race to the turn in 29.
Any thoughts of breaking 60 were put on hold when the 31-year-old bogeyed the tenth, but gains at the 13th and 14th took him to eight under with four holes remaining.
That was two shots clear of Scotland's Connor Syme, who went out in 31 before birdieing the tenth, with the Spanish presence at the top of the leaderboard bolstered by Pablo Larrazábal and Carlos Pigem in third and fourth respectively.
Larrazábal was five under through eight, with Pigem reaching the same mark before making a bogey on the eighth to drop to four under through ten.
David Drysdale was one over at the turn on his 500th European Tour appearance, while Miguel Ángel Jiménez was among the later starters as he prepared for a record 707th European Tour event.