Charl Schwartzel raced to a 10-stroke lead after three rounds of the Alfred Dunhill Championship by shooting a second straight 8-under 64 on Saturday to move him to the brink of back-to-back titles.
The South African left joint overnight leader Gregory Bourdy of France trailing after he birdied five of his first eight holes and then had four birdies in a row from No. 12 to sit at 21 under.
The 2011 Masters champion repeated the dazzling form that won him the Thailand Golf Championship by 11 shots last week.
Bourdy was alone in second on 11 under.
Sweden's Kristoffer Broberg, South Africa's Branden Grace and England's Steve Webster were 11 shots off the lead in a tie for third on 10 under.