Saud Shakeel hit an attacking century and, along with overnight partner Agha Salman, helped Pakistan take the lead against Sri Lanka on the third day of the rain-hit first Test on Tuesday.

The tourists reached 313-6 at lunch, one run ahead of Sri Lanka's first innings total, after a delayed start to the day due to rain and a wet outfield in Galle.

Left-hander Shakeel, who started the day on 69, was batting on 119 alongside Noman Ali on 13.

Shakeel, playing in his sixth Test, hit a boundary and took three runs to raise his second Test ton in a 177-run stand with Salman, who soon fell stumped to off-spinner Ramesh Mendis on 83.

The pair rescued Pakistan from a precarious 101-5 on day two as they took on the Sri Lankan spinners led by left-armer Prabath Jayasuriya, who rattled the visitors on Monday with three top-order wickets including skipper Babar Azam.

Both Shakeel and Salman scored runs briskly and hit regular boundaries but the run rate dipped after Salman's departure.