Ernie Els carded a five-under 67 to share a three-way lead midway through the first round of the South African Open on Thursday.

Els had four birdies and an eagle with only one bogey to join countryman Trevor Immelman and Spain's Carl Suneson at the top of the leaderboard.

In difficult windy conditions Els, who started on the 10th, went out in one-under 36. But birdies on the par-four fifth hole, the par-three sixth and an eagle on the par-five seventh, turned his round with an inward loop of 31.

"Before I went out I would have taken 67 for sure," Els told reporters. "When I started I wasn't sure what the wind was going to do, but it seemed to blow consistently."

Immelman made eagle in the 350-yard par-four ninth, his 18th, by holing a 35-foot putt after driving the green.

Defending champion Retief Goosen had just started his round. He was paired with Lee Westwood.