Bangladesh revived their World Cup campaign with an impressive bowling display to beat Ireland by 27 runs in Dhaka.
The co-hosts were dismissed for 205 after opting to bat first as Ireland's collection of medium pacers and spinners proved difficult to get away on a slow pitch, particularly Andre Botha (3-32) and George Dockrell (2-23).
But Ireland's batsmen also struggled to come to terms with conditions as they missed the chance to repeat their heroics of the last World Cup, when they claimed the scalps of Pakistan and Bangladesh.
Several of the top order got out after making starts and, although they remained up with the required rate throughout, lost regular wickets on the way to being all out for 178 in 45 overs.
Niall O'Brien (38) looked to have things under control until Tamim Iqbal pulled off a fine catch running in from the boundary to get rid of him in the 28th over, a dismissal that turned the game.
Ireland lost their last five wickets in the space of 8.2 overs, seam bowler Shafiul Islam finishing with career-best figures of 4-21 as the Tigers bounced back from their defeat to India in the tournament opener.
Tamim and Imrul Kayes gave the crowd plenty to cheer about in the first powerplay as the total reached 50 in just 5.4 overs before Ireland hit back with three quick wickets.
Kayes (12) was stumped smartly by Niall O'Brien off John Mooney before Junaid Siddique was run out for three attempting a quick single.
Botha made it three down when he had the dangerous Tamim caught slashing to point for 44.
Shakib Al Hasan struck three boundaries in his 16, but Botha nipped the Bangladesh skipper's innings in the bud, catching him off his own bowling.
Raqibul Hasan (38) and Mushfiqur Rahim (36) lent stability to the innings with their patient approach, taking 109 deliveries to put on 61 for the fifth wicket.
However, Ireland regained the initiative as Dockrell - who bowled one of the tightest spells of the tournament to date - removed Mushfiqur Rahim and newcomer Mohammad Ashraful (1) in successive overs, while Andrew White's quick fielding saw Raqibul run out.
The last three batsmen added a crucial 49 runs before being wrapped up by Botha and Trent Johnston, who ended with figures of 2-40.
In reply, Ireland lost both their openers - Paul Stirling (nine) and skipper William Porterfield (20) - by the 10th over and were left reeling at 75-3 when Ed Joyce (16) was tamely caught-and-bowled by Ashraful.
Niall O'Brien was soon joined in the middle by his younger brother Kevin when White (10) was bowled by Ashraful and Bangladesh kept the pressure going with Niall's dismissal off a superb catch by Tamim.
Kevin kept things steady - notching up a useful 41-run stand with Botha - but was caught in the deep for 37 off Shaiful and three quick wickets then further deepened Ireland's woes.
Mooney (0) was bowled by Naeem Islam and followed in similar fashion by Botha (22) off Shaiful, who also trapped Johnston lbw for six.
Fittingly, it was Shaiful who kicked off Bangladesh's victory celebrations when he dismissed Boyd Rankin for three.