Forced into a play-off versus Marcus Kinhult in Sun City, Fleetwood saved par to earn his first win of the season - his fifth European Tour victory in total.
A delighted Fleetwood spoke to Sky Sports following his win, and, reflecting on the victory, the prize money and his family, the 28-year-old needed a moment to compose himself.
Fleetwood said: "The money's not that important... I guess, being a golfer these days, you have a chance to set your family up for life, and...", before pausing to wipe away the tears after a lucrative win.
Fleetwood fired a spectacular final-round 65 to take the clubhouse lead on 12 under par at the Gary Player Country Club, but then had to wait for the field behind to see if he had done enough.
A 68 from Kinhult forced the play-off, which Fleetwood won with a par at the first extra hole, the 18th, as the Swede bogeyed.
Fleetwood went into the final round seemingly out of contention as he trailed overnight leader Zander Lombard by six shots on five under.
But while Fleetwood's 65 included a remarkable three eagles and four birdies, as well as three bogeys, South African Lombard fired a miserable 77 that included a double bogey and four other bogeys, dropping him to six under.
Bernd Wiesberger, who could have won the Race to Dubai a week early with a victory, eventually tied for third on eight under alongside Thomas Detry and Jason Scrivener.
Additional reporting by PA.