Confident Sangakkara gives Sri Lanka firm control 0
Samaraweera proved an effective ally for Sangakkara in a fourth-wicket stand of 94 before being bowled by Tahir.
Angelo Mathews (3) chased after a short delivery from Steyn that was way outside off-stump and ended up edging a simple catch to Boucher.
Wicketkeeper/batsman Chandimal then joined Sangakkara and helped add 104 for the sixth wicket as the South African bowlers lost their bite in cool, overcast conditions.
Sangakkara dragged Sri Lanka out of trouble after they had slipped to 20 for two, but the tourists could have been in serious difficulty if a chance he offered in the first over of the day had stuck.
Sangakkara, on his overnight score of three, edged Morkel to the slips, the catch heading straight to Graeme Smith at first slip, but Boucher reacted late, flinging out his glove in front of the captain’s face, distracting him and causing him to drop the catch.
The start of play was delayed for an hour while the outfield dried after morning and overnight rain.
Two wickets fell in the play that was possible, with Morkel claiming the wicket of Tharanga Paranavitana for nine in the seventh over of the day. The opener pushed firmly outside the off-stump at a delivery that bounced more than expected and moved away, Ashwell Prince taking a diving catch in the slips.
Leading run-scorer Mahela Jayawardene, who became the first Sri Lankan and ninth batsman overall to reach 10,000 test runs in the first innings, had scored 14 when he shouldered arms to a delivery from fast bowler Marchant de Lange that nipped back in off the pitch and trapped him lbw.