Batting first, Ireland posted 243 for seven, their highest total of the tournament and the first double-figure opening partnership after Porterfield, dropped on 42, raised 92 runs with Jeremy Bray (31).

22-year-old Porterfield missed the chance to emulate Bray with a century in the tournament when he skied an improvised sweep against paceman Mashrafe Mortaza to short fineleg in the 42nd over.

Kevin O'Brien hit 48 off 44 balls and skipper Trent Johnston, who elected to bat, 30 off 23 balls to add 77 in the last 10 overs. They were also helped by the fact that Bangladesh were poor on the field and dropped three catches, although they achieved four run outs.

Ireland made sure they did not suffer a repeat performance of their batting collapse -- when they were all out for 91 -- against holders Australia.

Having earmarked the match against Bangladesh as the one Super Eights match they could win, Ireland began steadily. The openers were well-set until Bray and number three Eoin Morgan (5) were both run out, but Porterfield held one end up and kept the scoreboard ticking steadily.

The left-hander, playing in his 15th one-dayer, was lucky on 42 after left-arm spinner Mohammad Rafique dropped a simple return catch after a casual one-handed attempt.

Porterfield's 136-ball knock contained only three boundaries and was a tale of patience and determination as he batted for nearly three hours to contribute two crucial partnerships.

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