Matt Wallace remained five shots clear once the Open de Portugal at Morgado Golf Resort second round was completed.
Bad weather over the first two days had caused delays, but brighter conditions in Portimão allowed round two to be finished on Saturday morning.
Wallace started the day 16 under with four holes to play and picked up a birdie on the ninth, his last, to complete a second round 66.
That gave him a bogey-free halfway total of 17 under par.
Germany's Sebastian Heisele recovered from a bogey on the sixth with back-to-back gains to post round of 70 and remain five shots adrift in second.
Wallace's fellow Englishman Jamie Rutherford and American Julian Suri were tied for third on 11 under after both reached the halfway stage on 11 under.
The 27 year old Wallace won six times on the Alps Tour last season to earn his Challenge Tour card.
Five of those titles came in consecutive appearances and in his three other starts on one of Europe’s four satellite tours, Wallace finished second, tied third and joint fourth.