Sri Lanka bat on in Chittagong

Kusal Mendis and Dhananjaya de Silva piled on the runs to put Sri Lanka in a comfortable position on the third day of the first Test against Bangladesh in Chittagong.

Birthday boy Mendis just missed out on a double century, hitting an impressive 196, while de Silva added 173 as Sri Lanka reached 3-504 at stumps, trailing Bangladesh's first innings total by just nine runs.

Roshen Silva was unbeaten on 87 alongside skipper Dinesh Chandimal, 37 not out, when stumps were drawn at the Zahur Ahmed Chowdhury Stadium.

Left-arm spinner Taijul Islam gave Bangladesh a rare occasion for joy on an arduous day when he removed Mendis just before the tea break.

Pace bowler Mustafizur Rahman earlier broke Mendis' 308-run second wicket stand with de Silva, who added 69 runs to his overnight 104.

De Silva and Mendis dominated the Bangladesh bowlers for nearly two sessions after Sri Lanka resumed their innings on 1-187.

The hosts had to wait for the second new ball to get their first success as Mustafizur got a leading edge from de Silva and wicketkeeper Liton Das took a high catch.

De Silva faced 229 balls and hit 21 fours along with a six in his fourth Test century and the second in as many Tests.

Mendis, who faced 327 balls for his career best innings as he turned 23, added another 107 runs with Roshen Silva for the third wicket before he gave a catch to Mushfiqur Rahim at mid-wicket.

"I think he is so disappointed," said Sri Lanka batting coach Thilan Samaraweera.

"The bigger picture is that if he had scored those two double-hundreds, it would have been very special for a 23-year old," Samaraweera said of Mendis, whose previous career best was 194 runs.

Bangladesh team director Khaled Mahmud admitted that Sri Lanka were now in the driving seat. 

"(It) is very important for us to see how quickly we can bowl them out (tomorrow) and then bat well in the second innings," he said.

Mendis hit left-arm spinner Sunzamul Islam for a boundary to bring his fourth Test hundred off 200 balls.

De Silva reached his 1000 runs in Tests on 154, joining Roy Dias as the quickest Sri Lankan to achieve the feat in his 23rd innings.