Dinesh Chandimal and Dhananjaya de Silva survived till the final ball as Sri Lanka ended the first day of the second Test with 314/4 against Bangladesh in Chattogram.
Bangladesh managed to pick up two wickets of Kusal Mendis, 93, and Angelo Mathews, 23, in the final session of the day
Earlier, Karunaratne was dismissed by Hasan Mahmud on the stroke of tea, hammered 86 off 129, smashing eight fours and one six.
After opting to bat first, the visitors made a fluent start with Nishan Madushka and Karunaratne dealing with the Bangladeshi bowlers with ease to keep the scoreboard ticking.
Madushka drove pacer Syed Khaled Ahmed for a four-pass point in the first over to justify his captain’s decision to bat first.
Karunaratne also began with a boundary when he clipped a full-length delivery of debutant Hasan Mahmud past mid-wicket.
But Bangladesh bowlers created some chances in an otherwise barren session but the fielders couldn’t hold on to it.
Madushka was dropped on 9 when Mahmudul Hasan Joy put down a straightforward chance off fast bowler Mahmud at second slip.
His opening partner Dimuth Karunaratne was also lucky to have survived as he top-edged a Mahmud delivery but Shakib Al Hasan fumbled it over the boundary line to give Karunaratne a six.
Madushka reached his second 50 off 80 balls when he punched off-spinner Mehidy Hasan Miraz to mid-off for a single.
Just after his half-century, he was trapped run out, giving Bangladesh a breakthrough after sharing 96 runs with Karunaratne for the opening stand. Madushka finally scored 57 off 105 balls, hitting six fours.
Karunaratne raised his 37th Test half-century off 93 balls, hitting pacer Khaled a boundary past mid-off.
Hasan Mahmud who bowled some probing spell on debut, finally got the better of Karunaratne for his maiden Test wicket when the batter dragged a length delivery back onto his stump.
The dismissal ended the threatening 114-run partnership between Karunaratne and Kusal.
However, Kusal who brought up his 18th Test 50 off 87 balls saw off the session with Mathews without any fuss.
Hasan Mahmud picked up two wickets so far while Shakib Al Hasan got one.