SUN CITY, December 8, 2013 (AFP) - The 42-year-old carded a final round 65 for a total of 268 at the Gary Player County Club, finishing ahead of Spaniard Sergio Garcia and overnight leader Welshman Jamie Donaldson.
Bjorn hit two eagles on the back nine to stun Garcia, who also struck 65.
It was Donaldson who led the way entering Sunday having been a model of consistency this week, hitting 67s either side of a second round 66.
He began in the manner you might expect given his advantage heading into the final day, producing four successive pars.
Birdies at five and seven added some impetus; however, Donaldson gave a shot back at the ninth to ensure he had company in the shape of Garcia at the summit.
With his iron play stupendous, the Spaniard began with back to back gains that were complemented by three pars in a row.
As solid a beginning as that was, further fireworks were necessary and he proved up to the challenge, producing a streak of four birdies from the sixth.
All the while, Bjorn had stayed hot on their heels courtesy of strokes picked up at two, six and nine.
It was after the turn, though, that he really caught fire, producing a stunning eagle at ten to suddenly leapfrog the pair.
Pars thereafter kept Bjorn in prime position but, having been joined by Garcia, he picked up a further two shots at 14 to reclaim the lead.
It was that effort that ultimately derailed the challenge from the Ryder Cup Winner, whose bogey at 16 ruined successive gains.
Three stokes in front by that point, the veteran Björn did not blink as pars at the next two virtually sealed his triumph, so much so that a drop on 18 meant little. He ultimately finished two strokes ahead of Garcia and Donaldson.
The latter ended his week with a disappointing 70, a birdie on 17 representing his only one coming in.
Collated final round scores and totals on Sunday in the European & Sunshine Tour Nedbank Golf Challenge at the Gary Player CC, Sun City, South Africa
(Gbr & Irl unless stated, par 72):
268 - Thomas Bjorn (DEN) 67-70-66-65
270 - Sergio Garcia (ESP) 66-73-66-65, Jamie Donaldson 67-66-67-70
272 - Henrik Stenson (SWE) 69-67-69-67
273 - Brendon De Jonge 70-68-69-66
275 - Charl Schwartzel (RSA) 68-70-71-66
276 - Justin Rose 73-67-69-67, Ryan Moore (USA) 71-65-67-73
277 - Thongchai Jaidee (THA) 69-70-66-72
279 - Peter Uihlein (USA) 70-69-70-70
280 - Gonzalo Fdez-Castano (ESP) 67-72-72-69
282 - Francesco Molinari (ITA) 76-70-69-67, Darren Fichardt (RSA) 71-68-69-74
283 - Louis Oosthuizen (RSA) 74-69-67-73, Richard Sterne (RSA) 73-73-71-66
Selected
290 - Matteo Manassero (ITA) 72-74-72-2
300 - Ernie Els (RSA) 75-71-77-77