Sri Lanka, replying to Pakistan's first innings total of 451, were 1-99 at stumps on Thursday's second day of the first Test in Galle.
Kaushal Silva was unbeaten on 38 and Kumar Sangakkara was not out 36. Upul Tharanga was the batsman out for 19.
Earlier, Younis Khan top-scored for Pakistan with 177 and Sri Lankan spinner Dilruwan Perera grabbed the last five wickets as the tourists were bowled out just before tea.
Younis led a valiant fightback with the lower-order batsmen as Pakistan gained the upper hand on day two after being 2-19 on the first morning.
Sri Lanka replied with 1-99 by the close, comfortably tackling both pace and spin, but the batsmen will remain wary of the turn and bounce that will increasingly come into play over the next three days.
Left-arm seamer Junaid Khan trapped Tharanga lbw in the fifth over, but Silva and Sangakkara settled in to put on 75 for the second wicket.
Silva was unbeaten on 38 and Sangakkara was on 36 with Sri Lanka still 352 runs behind the tourists.
"This game is still wide open even though there is some turn and bounce in this wicket," said Younis Khan.
"The third day's play tomorrow will be very crucial. If we can get some early wickets, then we can put them under pressure. I thought we were unlucky not to get more than one wicket today.
"But Sri Lanka too have some very good batsmen who are capable of putting up a big score. A lot will depend on how our spinners, Saeed Ajmal and Abdur Rehman, bowl in the morning."
The 36-year-old Younis, playing his 90th Test, batted for eight hours and 16 minutes, hitting 15 boundaries and a six in his 24th century.
Pakistan, who resumed at 4-261, went to lunch on 5-347 with Asad Shafiq making 75 during a fifth-wicket stand of 137 with Younis.
The visitors added 32 runs in the first hour when left-arm spinner Rangana Herath broke through for Sri Lanka by trapping Shafiq lbw. The batsman's appeal to the TV umpire went in vain.
Sri Lanka came close to removing Younis when he was on 156, but seamer Shaminda Eranga spilled a sharp return catch as the batsman failed to keep a drive along the ground.
Offspinner Perera, who had gone without a wicket for four sessions, struck five times in the post-lunch period to Pakistan's innings.
Perera ended Younis' vigil soon after lunch by beating the well-set batsman in the air, resulting in an easy catch at short mid-wicket, a soft dismissal that came against the run of play.
Pakistan's wicketkeeper Sarfraz Ahmed made 55 and shared a sixth-wicket stand of 66 with Younis when he also lobbed an easy catch to mid-on to give Perera his second wicket.
The offspinner had Saeed Ajmal and Junaid caught at leg-slip by Mahela Jayawardene, taking the retiring former Sri Lankan captain's tally to 202 Test catches.
Only India's Rahul Dravid has taken more catches (210) by a fielder other than a wicket-keeper.
Tailender Rehman, essentially a left-arm spinner, showed his batting skills by hammering six fours and a six while making 50, his second Test half-century.
Rehman's heroics enabled Pakistan to add 92 for the last four wickets after Khan's dismissal.
"This is a different Galle pitch," said Herath. "There may be some turn and bounce, but it is also easier to score runs.
"If we put up a huge total, it could be an interesting game."
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