Tournament host Sergio Garcia was one of 15 players separated by just five shots as the Spanish Open headed for a thrilling finish at Valderrama on Sunday.
Garcia began the final round six shots off the lead held by France's Michael Lorenzo-Vera, but took advantage of the calm, overcast conditions to birdie the third, fourth and eighth to reach the turn in 32.
And when the world number 16 also holed from 18 feet for another birdie on the 12th, he was just two behind leaders Andrew Johnston and Joost Luiten on a course where he won the Andalucia Masters in 2011.
With Lorenzo-Vera quickly dropping down the leaderboard with three bogeys in the first four holes, two-time major winner Martin Kaymer briefly enjoyed a two-shot lead when he holed from five feet for a birdie on the third.
However, playing partner Luiten then birdied the fourth and fifth to get on level terms before Kaymer bogeyed the seventh after a wild drive meant he had to chip out sideways from the trees.
Johnston had dropped a shot on the first but then picked up shots on the seventh and eighth to join Luiten at the top of the leaderboard, with Kaymer and halfway leader Pablo Larrazabal a shot behind.
Larrazabal had followed birdies on the first two holes with a bogey on the third, but then holed out from a greenside bunker on the seventh to reignite his bid to win his national Open for the first time.