Spinners placed Sri Lanka on the verge of a series sweep

Prabath Jayasuriya and Kamindu Mendis struck twice each as Bangladesh went seven down entering the final day.
Bangladesh 178 and 268 for 7 (Mominul 50, Mehidy 44*, Kamindu 2-22, Kumara 2-41) trail Sri Lanka's 531 and 157 for 7 (Mathews 56, Mahmud 4-65, Khaled 2-34) by 242 runs.
Sri Lanka resumed their march toward a 2-0 series triumph on day four, collecting seven Bangladesh wickets while facing minor pushback from the opposition. Mominul Haque reached fifty as Bangladesh attempted to bat out nearly five and a half sessions to rescue the match or score the record 511 runs required to win. Mehidy Hasan Miraz was undefeated at stumps, but no one else scored more than 40 runs, with Litton Das and Shakib Al Hasan putting up 61 for the fifth wicket.
For the first match in the series, Sri Lanka relied heavily on spin, even though the Chattogram surface had yet to take a substantial turn. It also did not provide much seam movement, pace, carry, or reverse swing, which the seamers were seeking for late in the day. The key for Sri Lanka was to be patient and continue asking varied questions of the Bangladesh hitters.

With so many runs to defend, Dhananjaya de Silva was unafraid to keep catchers close and experiment with unconventional attack strategies. Bangladesh's batsmen may be counted on to give up eventually. No one lasted longer than 74 balls.
Prabath Jayasuriya bowled 20 overs, taking 2 for 79. Lahiru Kumara also claimed two wickets, while Vishwa Fernando dismissed Zakir Hasan, who hit a fifty in the first innings. The two wickets taken by Kamindu Mendis surprised Sri Lanka, as he gleaned more turns, but less skillfully, than the more seasoned spinners. Kamindu can also bowl left-arm spin, but he stuck to off-breaks on this occasion, taking Shakib for his first Test wicket and sending Shahadat Hossain out lbw to conclude the day with 2 for 22.
Earlier in the day, Angelo Mathews became Sri Lanka's last batter to reach fifty in this match, with the rest of the top seven doing so in the first innings. He was out to a magnificent delivery from Shakib, who did not celebrate with much gusto despite the two's "timed out" history. Sri Lanka just batted till their lead reached 500 and then allowed Bangladesh the final 40 minutes before lunch to finish, which they did unscathed, albeit wickets fell shortly after.

Mahmudul Hasan Joy was the first out, in the second over after the break when Jayasuriya's slider knocked off his middle stump. Zakir didn't last long, either, giving Vishwa an edge at first slip. They continued to flounder. Najmul Hossain Shanto, who has had a poor series, had the top of his off stump rocked by a brilliant Kumara delivery angled in from the outside of the crease. Mominul, Bangladesh's finest batsman in Tests, reached his 18th career fifty off 55 deliveries before top-edging a sweep off Jayasuriya and was caught at deep square leg.

The Shakib-Litton stand offered a break from the wickets. They gathered singles carefully, and both began to strike confident boundaries while fending off quick-ball barrages on a pitch that had lost pace. However, they fell before really making Sri Lanka sweat. Kamindu had Shakib edging into the gully with an off-break that turned more than the batter expected, and Litton toe-edged a Kumara bouncer to the wicketkeeper as he attempted to collect it from wide off.
Bangladesh needs 243 runs, but more realistically, rain on day five to avoid what appears to be an unavoidable series finish. Their last two batsmen, Mehidy Hasan and Taijul Islam were at the crease at stumps.