SL vs BAN, 1st Test: Kusal Medis' unbeaten ton guides Sri Lanka to 321/4 at stumps on Day 1

Galle: Kusal Mendis made the most of a first-ball reprieve and went on to score an unbeaten century Tuesday as Sri Lanka posted a commanding 321-4 in the first Test against Bangladesh.

Mendis remained unbeaten on 166 at stumps after sharing a 196-run stand with Asela Gunaratne (85) for the fourth wicket at Galle International Stadium on the opening day of the two-Test series.

Bangladesh pace bowler Subashis Roy thought he had Mendis out for a golden duck when wicketkeeper Liton Das dived to his right to take a catch off an inside edge.

But a TV replay showed the bowler had overstepped, prompting the umpires to declare a no ball and enable the 22-year-old Mendis to go on to compile his second Test century.

"I may have played a false stroke the first ball I faced," Mendis said at the end of opening day`s play.

"After I played that shot I got a second opportunity to do justice to my team."

Mendis reached three figures with a straight four off Soumya Sarkar in a 242-ball innings that has so far featured 18 fours and two sixes.

Mendis and Gunaratne`s massive partnership put the hosts firmly in control of the match by close of play after they were 92-3 at one stage.

Gunaratne, who replaced injured regular skipper Angelo Mathews in the starting lineup, hit seven fours in his second half-century in three Tests before he was bowled by Taskin Ahmed.

The pair came together after the injury-plagued fast bowler Mustafizur Rahman, playing his first Test since August 2015, removed Dinesh Chandimal.

Chandimal managed to score just five runs despite facing 54 balls before edging a catch to Mehedi Hasan at gully.

Bangladesh started the day in positive fashion after stand-in Sri Lanka skipper Rangana Herath won the toss and asked them to bowl first on a flat pitch.

The visitors struck in the sixth over when Roy beat opener Upul Tharanga with a perfect inswinger to uproot his middle stump before the no-ball denied him Mendis`s wicket off the next ball.

Mendis and Karunaratne put on 45 for the second wicket before Bangladesh`s 19-year-old spinner Mehedi struck, bowling Karunaratne through the gate.

Mehedi later lamented lack of turn for the spinners from the pitch.

"There was really not much help from the wicket for the spinners," he said.

"Their batsmen played well, especially Kusal Mendis. If he had gotten out things would have been different," he said.

Bangladesh omitted left-arm spinner Taijul Islam from their side after the selectors opted for a three-man pace attack.

Liton was keeping wicket for the tourists after captain Mushfiqur Rahim, wanting to concentrate on his batting, handed him the gloves.

The hosts went in with three spinners, meaning all-rounder Dhananjaya de Silva missed out after playing the last Test during Sri Lanka`s recent tour of South Africa.

The second Test, which will be Bangladesh`s 100th, will be in Colombo from March 15-19.