The 27-year-old KTM rider, who bases himself in Dubai finished well ahead of his nearest rival, Austrian Matthias Walkner, to today take the title.
Sunderland took the 12 stage race by the scruff of the neck on stage five and did not relinquish the lead thereafter.
Speaking before the last stage he said: "I won’t let myself believe it until it’s done."
Completing the 64km final stage in 32:06:22, Sunderland romped home to victory in the race from Asuncion in Paraguay to Rio Cuarto, Argentina.
It was a case of third time lucky for Sunderland having withdrawn from the race in 2012 and 2014 following mechanical problems.
Fellow KTM rider Lyndon Poskitt was the second Briton home, over eight and a half hours down on Sunderland in 39th place.
Max Hunt came 52nd and 53-year-old David Watson finished 84th out of the 96 finishers in the motorbike category.
French driver Stephane Peterhansel held off the challenge of compatriot Sebastien Loeb to win his seventh cars title by just over five minutes.