Bangladesh opener Tamim Iqbal fell three runs short to his 36th half century as he caught behind playing a good length ball by KJ O'Brien and taken by the keeper getting a thin edge.
Tamim hit 47 off 54 with six boundaries before his dismissal. Bangladesh lost its first wicket at 95 on 13.5 over.
Mashrafe bin Mortaza led Bangladesh side has a steady start with two openers Tamim Iqbal and Soumya Sarkar chasing 182-run target set by host Ireland in Malahide in Dublin on Friday.
After facing eighth over, Tigers scored 42 runs without losing any wicket.
Tamim Iqbal was at 24 off 35 with three boundaries shot while Soumya Sarkar hit 13 off 13 with one boundary and one over boundary shot.
In this Tri-Nation series Bangladesh has not got any success yet, the Tigers are very much thirsty of a victory in their third match in the series against Ireland today and they are seemed confident to turn the match a success.
Aiming at a victory, Bangladesh skipper Mashrafe Mortaza won the toss and chose to bowl against Ireland in Malahide.
In his returning in rhythm after a long time gap, Bangldesh speedster Mustafizur Rahman stormed four wickets hunt against Ireland and wrapped up the host within 181.
Both teams made a change each to the XIs from their previous matches. Bangladesh handed a debut to 27-year-old left-arm spinner Sunzamul Islam, who replaced Mehedi Hasan in the XI. Sunzamul, who is also a handy lower-order batsman, was a part of Bangladesh's ODI and T20I squads on their recent tour of Sri Lanka but did not get a game in either format.
Ireland welcomed Ed Joyce back after the batsman had missed the first two games due to a back niggle. Simi Singh, who made his debut against New Zealand, made way for Joyce.
Ireland, too, were in search of their first win in the tournament. The series opener in Malahide last week between the two teams was washed out with only 31.1 overs of play possible. Rain remains a threat for this game, too, with a few showers predicted for late afternoon.
Ireland: 1 William Porterfield (capt), 2 Paul Stirling, 3 Ed Joyce, 4 Niall O'Brien (wk), 5 Andy Balbirnie, 6 Kevin O'Brien, 7 Gary Wilson, 8 George Dockrell, 9 Barry McCarthy, 10 Tim Murtagh, 11 Peter Chase
Bangladesh: 1 Tamim Iqbal, 2 Soumya Sarkar, 3 Sabbir Rahman, 4 Mushfiqur Rahim (wk), 5 Shakib Al Hasan, 6 Mahmudullah, 7 Mosaddek Hossain, 8 Sunzamul Islam, 9 Mashrafe Mortaza (capt), 10 Rubel Hossain, 11 Mustafizur Rahman