Quinton De Kock scored his maiden Test half century on Thursday as South Africa reached 331-7 at lunch on the second day of their first Test against Sri Lanka.
De Kock struck 51 off 90 balls with six fours as South Africa made steady progress after resuming at 268-5.
Jean-Paul Duminy (22) and Vernon Philander (3) were still at the crease at the time of the break.
Left-hander De Kock, playing only his second test, carried his form from the preceding one-day series that South Africa won 2-1.
De Kock struck a century in the ODI series decider and looked set for a big score on Thursday before he was caught by Mahela Jayawardene at slip off a delivery from Dilruwan Perera that turned viciously to give a glimpse of what can be expected from the pitch in the coming days.
Earlier, Lakmal bowled Dale Steyn with a yorker after the batsman, who was yet to score overnight, made three runs off 20 balls.
Both Perera and Lakmal have taken three wickets each so far.
South Africa is looking to maintain its admirable away record and has not lost a series abroad since its last tour of Sri Lanka in 2006 under Ashwell Prince.
