After starting well, with an opening goal from David Mathews after four minutes, England lost their direction, allowing Ireland's Chris Jackson to equalise from the penalty spot in the 18th minute after a careless tackle by Adrian Simons had been penalised.
England required several good saves from goalkeeper Jon Ebsworth before they took control again in the 50th minute with a goal from Alistair Boyce. Five minutes later Mark Pearn was gifted a goal before Mathews collected his second. On the stroke of time, a lapse of concentration by Ebsworth gave Simon Kershaw Ireland's second.
Earlier in the day, Germany, came from behind to crush Belgium 6-1 with senior international Sasch Reinelt scoring twice.
The under-21s' victory, unfortunately, could hardly compensate for the seniors' worst-ever defeat, on Thursday night. They went down 10-0 to Australia in the first of a two-match Test series.
The England manager, David Whittle, was putting on a brave face yesterday as he prepared his side for today's second Test. The defeat was England's worst in 572 games, but Whittle said: "We are not writing ourselves off. We still believe we can beat them, although we are maybe a little less gung-ho."
England's starting line-up is unlikely to have many changes, although Whittle confirmed that tactics would be different. "We will aim to contain them rather than all-out attack, relying on counter-attacks," he said.
FOUR NATIONS UNDER-21 TOURNAMENT (Milton Keynes): Germany 6 Belgium 1; England 4 Ireland 2.Reuse content