Pakistan lose early wicket after Sri Lanka make 320
Pakistan's Junaid Khan (C) celebrates with his teammates after he dismissed Sri Lanka's Dhammika Prasad during the second day of the second Test in Colombo on August 15, 2014 - by Lakruwan Wanniarachchi
Khurram Manzoor put on 47 for the first wicket with Ahmed Shehzad before he was caught behind off left-arm spinner Rangana Herath for 23 two deliveries before the break.
Pakistan went to lunch at 47-1 with Shehzad unbeaten on 21 and Azhar Ali yet to score. The tourists will look for a substantial total that will enable them to force a series-levelling win.
Earlier, Sri Lanka's last two wickets added 59 useful runs to the overnight score of 261-8 before the hosts were all out 45 minutes before lunch.
Number 11 batsman Chanaka Welegedara returned unbeaten on 27 after adding 36 for the last wicket with Herath (17).
Opener Upul Tharanga top-scored for Sri Lanka with 92 on what remains a good batting pitch at the Sinhalese Sports Club.
Left-arm seamer Junaid Khan finished with five for 87, with all his five career five-wicket hauls coming against Sri Lanka.
Fellow seamer Wahab Riaz claimed three for 88.
Sri Lanka lead 1-0 in the two-match series after winning the first Test in Galle by seven wickets.