The tornament starts this Thursday.
The 39-year-old world No. 6 won the "African Major" at the 7 162m Gary Player Country Club with a 15-under total of 273 last year.
In April he successfully defended his Indonesian Masters title, and his $3-million prize money in 2012 already more than triples his winnings last year. A win at the Sun City entertainment resort in the north west of the country will add $1.25-million to that.
"I'd love to be the first to win three Nedbank Golf Challenge titles in a row," said Westwood.
"You just have to look at the names on the trophy to realise how special it is. It's not the winning margin that is important to me, but it's the coming back and defending the title that is so satisfying."
Organisers were also pleased at the prospect of a third win.
Breathing down his neck
"Defending champion Lee Westwood has become one of the greatest players in the history of this tournament, and he now has a chance to make history at Sun City this year," said tournament director Alastair Roper.
But some will be breathing down his neck.
Countryman Justin Rose (32) is the highest-ranked of the 12 players after his second place finish at the DP World Tour Championship last week.
South African Louis Oosthuizen (30) follows directly behind Westwood in seventh position on the Official World Golf Ranking. He lost in a playoff against Italy's Matteo Manassero in the Singapore Open last Sunday.
Oosthuizen and four others won European Tour titles this year Francesco Molinari, Paul Lawrie, Nicolas Colsaerts, and Peter Hanson.
Contender to watch
South Africa's Charl Schwartzel, 2011 Masters champion, will also tee off.
Hanson from Sweden is another contender to watch, having taken the BMW Masters in Shanghai in October after beating world number one Rory McIlroy.
Seven of the victorious European team in the Ryder Cup challenge are represented, including former world number one Martin Kaymer from Germany.
"There is no doubt that the balance of power in the global game currently rests with European golf, and we are proud to have some of the best players in Europe competing in this year's Nedbank Golf Challenge," said Roper.
"We have a strong South African contingent who represent the future of the game," he added.
"We have a field that has a total of 12 victories worldwide this year alone. So I think we can safely say that we have amongst the best and most in-form players in the game coming to Sun City." – AFP