Ireland lost by four runs to Namibia in their opening Group B match at the ICC World Twenty20 Qualifier tournament in Dubai on Tuesday.
Namibia won the toss and made 160-8, with Louis van der Westhuizen scoring 34 and Raymond van Schoor 31.
Spinners George Dockrell and Paul Stirling took three wickets each, and Alex Cusack two.
Ireland fell short with a score of 156-9 in reply, Gary Wilson top-scoring on 49 and John Mooney contributing 38.
Van der Westhuizen, who scored his 34 runs off just 16 balls, was the pick of the Namibian bowlers with figures of 2-37.
Stirling ended with figures of 3-20 and Dockrell 3-30.
Stirling was less successful with the bat, out for duck to the final ball of the first over.
Captain William Porterfield was next out for 11 before Kevin O'Brien hit four boundaries in a rapid-fire 20.
Wickets continued to tumble, with Ed Joyce gone for five, before Wilson and Mooney took the fight to Namibia.
They put on 71 - with 11 fours and a six between them - before being dismissed as the required rate crept up.
Ireland's last hope went with Mooney, who was run out with three balls remaining.
The other nations in Ireland's group are Kenya, Italy, USA, Scotland, Uganda and Oman, with the top three reaching the play-off stages.
Just two countries will progress from the 12-day tournament in the United Arab Emirates to September's main event in Sri Lanka.
The Irish team have reached the past two ICC World Twenty20s, in England in 2009 and the West Indies in 2010.
Ireland's ICC World Twenty20 Qualifier Pool B fixtures
Tuesday 13 March - Ireland lost to Namibia by four runs
Wednesday 14 March - Ireland v Kenya
Thursday 15 March - Ireland v Italy
Friday 16 March - Ireland v USA
Sunday 18 March - Ireland v Scotland
Monday 19 March - Ireland v Uganda
Tuesday 20 March - Ireland v Oman