Ireland 202 for 4 (O'Brien 84, Cusack 46) beat USA 124 for 6 (Thyagarajan 72*, Connell 4-14) by 78 runs

After the jubilation of their unexpected win over Scotland, USA came crashing back down today as Niall O'Brien's 84 lifted Ireland to a massive 202 for 4 and set up a 78-run win. Aditya Thyagarajan's unbeaten 72 saved USA's humiliation after they had slipped to 25 for 6 in their chase, but the result was already all but guaranteed after Ireland ratcheted up their highest total in Twenty20 cricket.

After the promising start in the win over Scotland, USA were badly let down by their bowlers today. William Porterfield and O'Brien stormed to 83 at 10 an over before Saurabh Verma found the edge of Porterfield's bat for 45, and after he departed Alex Cusack ensured there would be no let-up in the onslaught.

O'Brien looked set for a maiden Twenty20 hundred as he entered the 80s with 19 balls remaining in the innings, but it was not to be. He gave Timroy Allen the first of his two wickets to depart for 84, but by then the total had already passed 170. The other O'Brien - Kevin - came and went quickly, and Cusack was dismissed four runs short of a half-century, but Trent Johnston and Gary Wilson's late hitting took Ireland's score past 200.

Thoroughly demoralised after Ireland's blitz, USA's batsmen quickly capitulated in Peter Connell and Trent Johnston's opening spells. Three top order batsmen fell without scoring - including Captain Steve Massiah, to the first ball he faced - as USA crumbled to 11 for 5. Three overs later they slipped to 25 for 6, and it looked as though USA would struggle to survive past the halfway mark of their innings.

With only honour left to play for, the debutant Thyagarajan set about his task with gusto, collecting 11 fours in his innings and adding 99 with Orlando Baker to salvage some pride for USA. He was particularly severe on George Dockrell, the young left-arm spinner, and USA's final total was an admirable one after the depths of their collapse.

Ireland will be pleased with the extent of their victory in this game after their opening loss to Afghanistan, as they are now in strong contention for a Super Four berth. In theory, USA also still have a chance of going through to the next round, although they will have to inflict a resounding defeat on Afghanistan tomorrow which, on current form, looks highly unlikely.