Tournament host Sergio Garcia's hopes of winning a second Spanish Open title were fading fast on Saturday as Valderrama continued to provide a stern test.
Garcia began the third round on three over par but just six shots off the pace, with compatriot Pablo Larrazabal and England's Andrew Johnston the only players under par after the first two days.
With swirling winds making scoring even more difficult at the notoriously testing former Ryder Cup venue, Garcia had predicted that level par could be good enough to lift the title on Sunday.
However, the world number 16 could only cover the front nine in 38 after bogeys on the second, third and eighth to drop back to six over, eight shots behind new leader Johnston.
Johnston, who is looking to win his first European Tour title, had recovered from a bogey on the second with birdies on the fourth and fifth to reach two under, a shot ahead of playing partner Larrazabal.
Larrazabal had bogeyed the third and three-putted the short sixth, with fellow Spaniard Alejandro Canizares and England's Richard Bland a shot behind on level par.
Two-time major winner Martin Kaymer, who changed his plans to play on the PGA Tour this week after learning Valderrama would host the tournament, was two shots further back after following birdies on the fourth and fifth with bogeys on the seventh and ninth.
Source: PA
