India, hurt by spot-fixing allegations in their home Twenty20 tournament, forgot their worries to seize the initiative in Group B by smacking 331 for seven off their 50 overs and watching South Africa fail to get close.
The gamble to open with Colin Ingram backfired when he was caught in the slips for six and despite Ryan McLaren hammering 71 not out, the Proteas were bowled out for 305.
India opener Dhawan, in his sixth ODI, scored 114 off 94 balls as he stylishly dominated the inconsistent South African bowling attack which was already without stricken paceman Dale Steyn and lost Morne Morkel to a groin strain when bowling mid-over.
South African skipper AB de Villiers said: “We now have a very important game against Pakistan. We are going there to win. It’s do or die.”
ICC CHAMPIONS TROPHY
Today’s fixture: Group B: Pakistan v West Indies (The Kia Oval, 10.30).
Yesterday’s result: India 331-7 Innings Complete (S Dhawan 114, RG Sharma 65) v South Africa 305 (R McLaren 71 no, AB de Villiers 70, R J Peterson 68). India beat South Africa by 26 runs.