Kasun Rajitha took 5-56 as Sri Lanka bowled out Bangladesh for 182 in their second innings to clinch a 328-run victory in the first cricket Test.

Rajitha, who took 3-56 in the first innings, finished with career-best match figures of 8-112 in a Test.

Mominul Haque played a lonely defiant innings for the hosts, stranded on 87 from 148 deliveries when the final wicket fell in the middle session on the fourth day in Sylhet on Monday. His innings contained 12 boundaries and a six.

Bangladesh were set an improbable 511-run victory target after Sri Lanka rode on centuries in each innings from Kamindu Mendis and skipper Dhananjaya de Silva.

Sri Lanka made early inroads in Monday's morning session when Rajitha trapped Taijul Islam lbw for six in the second over after Bangladesh had resumed at 5-47.

Mominul and Mehidy Hasan combined for a 66-run seventh-wicket stand, but Rajitha struck again to break up the partnership.

Mehidy scored 33 from 50 deliveries before he played an expansive drive and got a thick outside edge.

Mominul then shared a 47-run partnership with Shoriful Islam (12) for the eighth wicket.

Rajitha broke that partnership when he took a return catch to dismiss Shoriful.

With his next delivery Rajitha had Khaled Ahmed caught by Kusal Mendis for a duck to complete the second five-wicket haul in his Test career.

Lahiru Kumara, who returned figures of 2-39, ended the Bangladesh innings by dismissing Nahid Rana for a duck.

After recovering from an early batting collapse at the start of the match, Sri Lanka posted 280 in their first innings, with de Silva and Mendis each scoring 102.

After then dismissing Bangladesh for 188, de Silva (108) and Kamindu (164) again hit centuries as Sri Lanka reached 418 in their second innings to set up victory.