Chris Wood shot a 1-under 69 to extend his Iberdrola Open lead to four strokes after Saturday's third round.
The Englishman had birdies at Nos. 1 and 10 to offset a bogey at the 14th, finishing at 9-under 201 to improve his overnight lead by one in a bid for his maiden victory.
Shane Lowry shot a 63 to equal the Pula course record set Thursday by Frenchman Gregory Bourdy, moving into a tie for second at 5 under with Darren Clarke of Northern Ireland, who had a 70.
An eagle 3 at the sixth propelled Lowry, who managed six birdies and a single bogey to jump 28 spots.
''It was one of those days when it all happened quickly and I was off and running,'' the Irishman said.
Jose Maria Olazabal of Spain managed five birdies after a bogey at No. 2 for a 66 that put him in fourth at 206.
Bourdy had a 67 and was tied with David Lynn (71) and Scott Jamieson (69) at 3 under.
Thomas Aiken of South Africa shot a 66 that moved him seven back of Wood a week after his win at the Spanish Open.
European Tour rookie Matthew Dixon, playing in the final group with Wood, stumbled to 76 to drop 10 shots back.