East London: Imran Tahir (4-28) and Vernon Philander (3-27) and Hashim Amla and Faf du Plessis hits unbeaten fifties as the South Africa beat West Indies in the third one-day international at Buffalo Park, East London on Wednesday.
In chase 123, the host lost Rossouw on 7, since then, du Plessis and Hashim Amla batted brilliantly and made sure that there were no more hiccups.
Faf registered his 12th ODI fifty. Amla's amazing form with the bat continued as he registered his 3rd consecutive 50-plus score in the series
Earlier, West Indies collapsed to 122 all out. Marlon Samuels made 26 but no other West Indian batsmen reached 20 in a dismal performance on a good pitch.
Philander took two wickets inside the first two overs and finished with three for 27, while leg-spinner Imran Tahir claimed a career-best four for 28.
It was no surprise that the West Indies batted first on a dry pitch expected to get slower and lower in the second half of the match, especially after they had conceded 439 for two after sending South Africa in to bat in the previous match in Johannesburg last Sunday.
But the tourists were in trouble almost immediately and were unable to mount any substantial partnerships.
Philander had opening batsmen Dwayne Smith and Chris Gayle caught behind and fast bowler Dale Steyn followed up with the wickets of Narsingh Deonarine and Denesh Ramdin as the West Indies stumbled to 43 for four.
Samuels looked the one batsman capable of playing a major innings before he was caught on the long-off boundary off Tahir.
Earlier, West Indies have won the toss and opted bat first.
Two changes for the tourists with Leon Johnson left out for Narsingh Deonarine, Darren Sammy is also out and in comes Carlos Brathwaite. South Africa are unchanged from Sunday's second ODI.
South Africa: Rilee Rossouw, Hashim Amla, Faf du Plessis, AB de Villiers (Capt. & wk), Jean-Paul Duminy, David Miller, Farhaan Behardien, Vernon Philander, Dale Steyn, Imran Tahir and Morne Morkel
West Indies: Chris Gayle, Dwayne Smith, Narsingh Deonarine, Marlon Samuels, Denesh Ramdin (wk), Jonathan Carter, Andre Russell, Carlos Brathwaite, Jason Holder (Capt.), Jerome Taylor and Sulieman Benn
West Indies - 122 (Tahir 4-27, Philander 3-27)
South Africa - 124/1 (Amla 61*, du Plessis 51*)
Result - South Africa won by nine wickets