Virat Kohli's classy century ensured Faf du Plessis' own gritty hundred counted for nothing as India beat South Africa by six wickets in Friday's first one-day international.

On a slow Durban pitch, Proteas captain Du Plessis ground out a gutsy 120 to help South Africa to 269-8 after India's spinners had the hosts reeling on 134-5.

The next best contribution came via Chris Morris' 37 and, as is so often the case, talismanic India skipper Kohli (112) came to the fore with his 33rd ODI century, aided brilliantly by Ajinkya Rahane's 86-ball 79.

India – beaten 2-1 in the Test series – reached their tally with 27 balls to spare to take a 1-0 lead in the six-match series.

South Africa had battled to 79-1 off 14 overs before the introduction of Yuzvendra Chahal (2-45) and Kuldeep Yadav (3-34), who had the home side's batsmen toiling.

Quinton de Kock (34), Aiden Markram (9), JP Duminy (12) and David Miller (7) all fell victim to the duo, before Du Plessis came to the rescue.

It was not as easy knock for the skipper, who would have walked lbw on 18 had India reviewed a Chahal appeal, but having survived the spinning onslaught he cashed in with 82 off 60 balls against the seamers.

Morris stuck around for a 74 partnership before being bowled by Kuldeep's full toss, but Du Plessis and Andile Phehlukwayo put on a half-century stand with the former sending Bhuvneshwar Kumar way over deep midwicket and giving Jasprit Bumrah the treatment before holing out to Hardik Pandya at extra cover.

South Africa were still in it when Rohit Sharma (20) edged Morne Morkel behind and Shikhar Dhawan (35) was run out, but they were unable to break the Kohli-Rahane partnership.

Kohli managed his innings with trademark poise, a couple of fours off Morris in the 19th over speeding up his knock towards fifty.

At the other end, Rahane provided an excellent foil swiping an Imran Tahir delivery over midwicket to bring up a hundred partnership before slapping Morris over the long-on ropes.

Two fours off Phehlukwayo in over 41 brought up the century for Kohli and, after Rahane had lobbed one to Tahir at long on, the skipper was afforded a standing ovation after the same bowler forced him into a hoick that Kagiso Rabada snapped up.

India effortlessly saw out the remainder of the chase to take a lead into the second match in Centurion.