Giovanni Trapattoni insisted the Republic of Ireland's UEFA EURO 2012 hopes were not over after one game, despite tonight's 3-1 opening defeat by Croatia. The Republic suffered a painful reintroduction to the game's elite this evening as they were outplayed to lose 3-1 in Poznan and leave themselves with a mountain to climb in Group C. Defeat against Spain on Thursday could spell the end for Trapattoni's men, who must realistically also get a result against Italy next Monday to stand any chance of progressing. The Republic looked worryingly out of their depth in what was their first major finals appearance for a decade and first at a European championship since 1988. But manager Trapattoni said: "We have to believe. This evening we met a strong team, technical - we knew that before. But every game in this EURO can be a surprise. We have to believe this. Until now, we have not conceded a situation like this evening." The Republic of Ireland got off to the worst possible start, conceding inside three minutes. They equalised in the 19th minute through Sean St Ledger, though, and had looked set to go into half-time level before a sucker punch two minutes from the break when Nikica Jelavic pounced on Stephen Ward's horrible error to make it 2-1. It knocked the stuffing out of Ireland, who allowed Mario Mandzukic to grab his second of the night three minutes after half-time.