Sri Lanka earlier put up a spirited display to restrict Pakistan to 176, with their bowlers removing the last six batsmen for 52 to gain a narrow lead.
Pakistan, resuming on 124-4, were in trouble as paceman Farveez Maharoof returned his best bowling figures of 4-52.
Maharoof, who captured two wickets off successive balls on Monday, struck in his first over of the morning. He removed skipper Inzamam-ul Haq (31) off his third ball as the batsman nicked one to wicket-keeper Sangakkara.
The 21-year-old, playing his ninth Test, struck again a few overs later when he bowled Abdul Razzaq with an in-swinger to reduce Pakistan to 138-6.
The entire first day was washed out by rain. The second and final Test will start in Kandy on April 3.
RSS