Defending champion Lee Westwood and under 68 Thursday to share the lead after one round of the Nedbank Golf Challenge.
Westwood was a runaway winner last year, finishing eight strokes clear of Tim Clark, and was also the runner-up in 2000. Schwartzel is playing this lucrative event for the first time.
World No. 1 Luke Donald headlines a logjam of players in fourth place. He posted a two-under 70 and was joined there by Graeme McDowell, Martin Kaymer, Simon Dyson, Jason Dufner and Kyung-Tae Kim, who are all playing this event for the first time.
Westwood tripped to a bogey on the first, but came right back with a birdie on the par-five second. After six pars in a row, he jumped into red figures with an eagle on the par-five ninth.
The Englishman birdied the 10th, but gave that stroke back with a bogey on the 11th. Westwood atoned for that error with a birdie on No. 15 and he closed with an 18-foot birdie putt at the last to share the lead.
Schwartzel started with three pars in a row before converting a birdie chance on the par-three fourth. After four more pars, he faltered to a double-bogey at No. 9 after finding water with his third.
The 27-year-old South African caught fire around the turn. He moved back to even-par with a birdie on No. 10, then poured in three consecutive birdies from the 12th to jump up the leaderboard. Schwartzel birdied the 16th to move to minus-four and parred the final two holes.
Donald had reached four-under with five birdies and a bogey through 14 holes. However, he double-bogeyed the 17th to fall two back.
NOTES: Despite the small the field, there is a $5 million purse for this event...Only six of the 12 players have competed in this tournament before and Westwood is the only former champion among those six.