(CNN) -- New Zealand's Mark Brown hit four bogeys in his last five holes to miss out on a share of the overnight lead after the second round at the Ballantine's Championship on Korea's Jeju Island, leaving Dutchman Robert-Jan Derksen with a two-stroke advantage.
Derksen coped best with the blustery conditions to take a two-stroke lead on Jeju Island.
Brown, who shared the overnight lead with Spain's Gonzalo Fernandez-Castano on seven-under-par, had posted two birdies and no bogeys after 13 holes on the second day at the Pinx Golf Club to join Derksen (69) on nine-under.
However, as rain fell in the afternoon, Brown struggled to cope with the conditions. He bogeyed the 14th, pulled it back with a birdie straight after, but then hit three bogeys in a row on his final holes to finish on one-over 73 for the day and fall back to six-under overall.
A number of players struggled to cope as the weather turned from light breezes and clear skies on Thursday to strong, blustery winds in the morning and heavy showers in the afternoon.
Derksen was one of the few able to tame the much-changed conditions, holing six birdies for a three-under 69, moving him onto nine-under overall.
Thongchai Jaidee (71) and Kang Wook-Soon (69) are joint second, two strokes behind the leader on seven-under-par, while Pablo Martin, the first amateur to win a European Tour event when he came first in Estoril in 2007, repeated his round of 69 to move up to six-under and join a three-way tie for third with Brown and Alessandro Tadini (71).
The conditions claimed some notable casualties, notably last year's winner Graeme McDowell, who followed Thursday's 76 with a one-over-par 73 to miss the cut by four strokes.
Joint first round leader Fernandez-Castano shot three consecutive bogeys during his two-over 74 to drop to five-under, while world number nine Henrik Stenson and three-time major winner Ernie Els are on two-under-par after both carding rounds of 74.