Victor Dubuisson moved into a two-stroke lead at the Nedbank Golf Challenge as stormy weather split the field in Sun City.
The Frenchman, chasing a spot in the top 60 of the Race to Dubai standings in order to be among the field at the season-ending World Tour Championship in Dubai next week, shot a measured 70 to close Friday's play on six under overall.
His nearest rivals are home hope Darren Fichardt and Lee Westwood, who is closely followed by fellow Englishmen Tyrrell Hatton and Ross Fisher at Gary Player Country Club, where there was a lengthy delay as storms closed in.
"I just try to play as good as I can each day, day after day," said Dubuisson. "Especially on this course, you've got to have a very solid game to do some good scoring.
"The driver of course here is the key if you want to play well and today I didn't miss many fairways, maybe one or two, and I played very solidly in the wind.
Overnight leader Bernd Wiesberger, who carded a 67 in fair conditions on Thursday, needed an extra 10 shots to complete his second round, leaving him back on even par.
Defending champion Alex Noren's 72 means he is three shots off the summit, while Race to Dubai leader Tommy Fleetwood is languishing nine strokes adrift of Dubuisson.
Fleetwood could wrap up the title in South Africa, but looks likely to have to wait unless he can produce something remarkable over the weekend.
Dubuisson's round, which was bettered only by Fichardt, major winner Martin Kaymer and compatriot Benjamin Herbert's 69s, was soured slightly by a bogey at the last.
Until that point he had dropped only one shot, making gains at four, six, 10 and 15.
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