Tillakaratne Dilshan and Kumar Sangakkara starred with the bat as Sri Lanka thumped South Africa by 128 runs in Colombo to run out comfortable 4-1 series winners.
Dilshan, who smashed an unbeaten 115 in Pallekele on Sunday, scored 99 and Sangakkara blasted 75 not out from just 45 deliveries as Sri Lanka posted an imposing total of 307-4.
South Africa made a solid start to their reply but the loss of opener Hashim Amla for 18 sparked a batting collapse, with the tourists crashing from 60-1 to 85-6 in the space of 10 overs.
AB De Villiers did provide some resistance with a run-a-ball 51, but the tourists were eventually bowled out for just 179 to complete another one-sided victory.
Opener Dilshan continued his prime form from Sunday's series-clinching win, striking 13 boundaries in a 110-ball innings before he was bowled by Ryan McLaren just one run short of his century.
Lahiru Thirimanne contributed 68 to a 163-run partnership with Dilshan, which carried Sri Lanka from 13-1 to 176-2 and laid a strong platform for Sangakkara to launch a late assault.
Sangakkara on song
Arguably the best wicketkeeper batsman in the world, Sangakkara struck 12 boundaries in a blistering innings which helped propel Sri Lanka past the 300-mark.
Sangakkara was supported Angelo Matthews (23) and Thisara Perera (17 not out) before Sri Lanka's bowlers went to work, tearing through the Proteas top order.
The tourists started solidly but ended meekly. Quinton De Kock contributed 27 in an opening stand of 35 and when JP Duminy joined Amla, South Africa moved to 60-1 inside 10 overs.
But their innings disintegrated after Amla was trapped leg before wicket by Sachithra Senanayke, who had also dismissed De Kock, for 18.
Dilshan snared Duminy in the same manner for 15 the next over and Thisara Perera had Faf du Plessis caught behind for six off before Lakmal dismissed Farhaan Behardien and David Miller in the space of three deliveries.
De Villiers stopped the rot with his half-century, McLaren scored 29 and Aaron Phangiso finished 18 not out.
What will be the result at Old Trafford?