Dilshan, Sangakkara secure series
Sri Lanka 239 for 2 (Dilshan 115*, Sangakkara 91) beat South Africa 238 (Duminy 97, Mendis 4-51)
Scorecard and ball-by-ball details
An unbeaten century from Tillakaratne Dilshan and 91 from Kumar Sangakkara carried Sri Lanka to a series win over South Africa with one match to play. The pair ensured the hosts achieved the highest successful run chase at Pallekele with six overs to spare to underline some of South Africa's most pressing issues as they attempt to rebuild their one-day side.
At first glance, it would seem the bowlers are to blame but South Africa's middle-order are the real culprits in their defeat. Hashim Amla and JP Duminy shared a second-wicket stand of 101 to set a strong base for the team but the batsmen who followed squandered the advantage.
From 118 for 1, South Africa were 238 all out, losing nine wickets for 120 runs. By contrast, Dilshan and Sangakkara shared a partnership of 184 - Sri Lanka's highest against South Africa - to maintain their strong record at home against South Africa.
South Africa have only won two ODIs in Sri Lanka and their inability to adapt to conditions was exposed again. The absence of quality spinners and senior players to take responsibility in the batting line-up cost them dearly and they will now return to Colombo with only pride to play for.
South Africa began to make some amends for their failings with the bat and Hashim Amla's return was central to that. Amla, who missed the first and third match with injury and could not bat in the second, recovered in time to form one half of South Africa's fourth opening pair in as many matches.
While Quinton de Kock's inexperience was exposed against Lasith Malinga, when he was yorked for 8, Amla had the Sri Lankan attack erring. The seamers continually offered him too much width and he pulled and cut at will.
Amla and JP Duminy, who has looked good without producing results in the series so far, settled in and took the batting powerplay after 15 overs. That proved a tactical mistake. Sri Lanka's slew of spinners limited run-scoring opportunities and only 22 were scored in the five-over period.
The pair succeeded in planting a platform but Amla did not stick around to help the launch from it. He was lbw to Dilshan, who went around the wicket to trap him on the back foot, and even a review could not save him.
AB de Villiers' lean run continued as he was caught behind trying to paddle-sweep. Faf du Plessis also did not contribute, offering a chance to Angelo Mathews in his follow-through and eventually being stumped.
Ajantha Mendis foxed the less-experienced players, who have not learnt to pick him. David Miller was bowled by the legbreak and Farhaan Behardien clipped him straight to short leg.
The fall of wickets forced Duminy to continue a quiet vigil and his strike rate remained in the 60s, until the last four overs, when he finally decided to launch against Malinga. Duminy managed to improvise, turning would-be yorkers into low full-tosses, but Malinga's change of pace accounted for the tail.
Still, South Africa would have thought they had enough with 198 the previous-best successful chase in Pallekele. Their bowlers started well against a changed Sri Lankan top order - with Mahela Jayawardene replacing Upula Tharanga - as Morne Morkel and Lonwabo Tsotsobe extracted extra bounce and got movement, but ill-discipline infected them again. South Africa sent down 17 wides, taking their series total to 58, and indicating an obvious problem with line.
Jayawardene was frustrated by the early squeeze and when he tried to steer Tsotsobe to third man, he was caught by a diving Amla at gully. That was the last success South Africa saw until it was too late. Dilshan showed a willingness to ride out the pressure and looked for singles with Sangakkara instead of going for big shots to thwart the bowlers.
But South Africa still had their chances. Sangakkara was on three when he edged Kleinveldt but Amla could not pull off the half chance, and on 33, when Duminy appealed for an lbw against him. South Africa had a review in hand but de Villiers chose not to use it. Afterwards, he said neither Duminy nor de Kock, who was keeping, were convinced, Replays, though, showed Sangakkara was out.
His flirtation with fortune over, Sangakkara matches Dilshan blow for blow thereafter. Dilshan was strong square of the wicket and on the pull and brought out his trademark scoop off Tsotsobe. His century came off 119 balls with a swivel down to fine leg.
Sangakkara peppered the on-side, with 52 of his runs coming in that area. After Dilshan crossed the century mark, Sangakkara was racing against the remaining runs to get there. He smacked Morkel for two fours to get into the nineties, but fell on his sword when he top-edged to mid-off.
Dilshan finished things off to leave South Africa with plenty to think about. Foremost in their minds will be their poor effort in the field, and their decision-making under pressure, both of which need work before Wednesday.
Firdose Moonda is ESPNcricinfo's South Africa correspondent