The third-wicket partnership between Najmul and Mominul reached 226 runs so far, which is now the fourth highest stand by a Bangladeshi pair in away Tests.
Mominul played 42 Tests before coming to this game and got stuck 10 centuries. But all of those centuries have been notched up on home soil. Before this game, his best in away Tests was 77, which is now surpassed by the left-handed batsman.
Earlier, on day one, Bangladesh won the toss and opted to bat first. They lost the opener, Saif Hassan, in the second over of the match. But the visitors recovered from that initial damage well, as Tamim Iqbal and Najmul put up a 144-run partnership in the second wicket stand.
This series is part of the World Test Championship. Bangladesh played five matches of this event but failed to win any of them while Sri Lanka played 10 matches and won one with losing six and drawing the other three.
Bangladesh played a total of 12 matches in Sri Lanka and won one of them in 2017 which was Bangladesh's last overseas Test win to the date.