South Africa took an unassailable 3-0 lead after the most closely fought game of the five-match series thus far, with the result settled in anticlimactic fashion by the Duckworth-Lewis method. Thundershowers interrupted play at the end of 34 overs of South Africa's chase, at which time the teams were on even terms but the hosts just four runs ahead mathematically. In that context, captain AB de Villiers' counterattacking, unbeaten 39 and his brief partnership with Albie Morkel, which included a retrospectively decisive 26 runs in the last three overs, settled the game for South Africa.

Batting down the order, at No.6, and promoting Faf du Plessis to No.4 proved a masterstroke from de Villiers, who showed excellent adaptability to a tricky situation posed by the weather. A light drizzle infused a sense of urgency in his approach, and by the time it had developed into pouring rain, he had taken his team past the required target. His efforts, together with du Plessis' fluent half-century earlier in the innings, undermined a spirited performance from Sri Lanka in the field and a much-improved show with the bat.

Three fours in an over against Kosala Kulasekara signalled the acceleration South Africa needed to get their noses ahead. de Villiers, in the 32nd over, smashed two deliveries through extra cover and walked across to clip one through square leg. The next over fetched five and what turned out to be the final over of the match yielded eight, including a wide and at least a run scored off every other ball. de Villiers and Albie Morkel had got together when their opponents held the advantage, following the run-outs of du Plessis and JP Duminy.

du Plessis revived South African hopes after an early double-strike from Lasith Malinga, and an irresponsible shot from a set Alviro Petersen, jolted the hosts, who were missing the services of two key batsmen - Jacques Kallis was rested and Hashim Amla out on paternal duties. du Plessis was fluent throughout. He timed the ball well, punching it firmly through the off side, subtly working the ball and opening the face on either side behind the stumps and crashing deliveries past the covers for a couple of boundaries. Duminy moved along steadily at the other end, picking up the singles and twos comfortably as the field spread, and collecting boundaries himself with some expert placement.

But just as it seemed South Africa were going to inch ahead due to that 61-run stand, Duminy, racing to the non-striker's end in the 24th over for a single, was given run-out by the third umpire Billy Doctrove. Nuwan Kulasekara scored a direct hit but the side angle showed Duminy to just have made it as the bails were knocked off, while the front-on angle showed the bat just on the line. As the big screen flashed "Out" there was disbelief on Duminy's face and in the South African dressing-room, where Gary Kirsten had his arms up in the air. It took an age for Duminy to walk off, and the pressure was back on the hosts again. A little more than five overs later, a cramping du Plessis departed, struggling to complete a quick single and found short as Kumar Sangakkara took off the bails. But as it turned out, he'd done enough for his captain to complete the job in time.

Angelo Mathews, the Sri Lanka vice-captain, had aimed for a target of 250 in this game and his team exceeded expectations. The openers, led by Upul Tharanga, with Tillakaratne Dilshan uncharacteristically playing second fiddle while recovering from two consecutive ducks, approached their innings methodically, forging a 94-run stand. The focus was on settling down and batting long, illustrated by only two boundaries being struck in the first 10 overs, both from Tharanga.

Both improvised, Tharanga smashing two sixes in the first over of spin and Dilshan pulling off his trademark scoop. But they kicked off a trend of batsmen being dismissed after getting starts and not converting them to something substantial, top-edging sweeps.

Sangakkara struck three delectable boundaries through different parts of the ground, including his favourite cover drive, but both he and Mahela Jayawardene were run out, thanks to brilliant pieces of fielding from du Plessis and Colin Ingram. Nuwan Kulasekara made a handy 40 down the order, and Dinesh Chandimal and Mathews chipped in.

But despite a collective effort with the bat, more energy and fight in the field, and the fact that the match was evenly poised when rain interrupted, Sri Lanka hadn't done enough.