Kumar Sangakkara completed an aggressive century on Monday as Sri Lanka took a 106-run lead over Bangladesh before being dismissed before lunch on the third day of the second Test.
After resuming the day on 6-296, Sri Lanka added just 50 runs for their last four wickets.
Bangladesh reached 0-23 at lunch, still trailing by 83 runs, with Tamim Iqbal on 13 and Jahurul Islam on 9.
Seamer Abul Hasan had Sangakkara caught behind on 139 for the morning’s breakthrough, while offspinner Sohag Gazi (3-111) cleaned up the tail.