Poland promised goals. They delivered one and it was enough for their first ever win at the European Championships.
Northern Ireland knew what to expect from the top scorers in Euro qualifying (33 goals). But their defensive 4-5-1 set-up still could not cope with Adam Nawalka's side.
Northern Ireland defended deep, and in numbers. To their credit, they kept Poland's dangerman Robert Lewandowski quiet.
But Poland played at a frantic pace from the start, with full-backs Artur Jedrzejczyk and Lukasz Piszczek joining the attack. It was just a matter of time before they were rewarded for dominating possession and shot attempts.
Poland forward Arkadiusz Milik lacked composure after creating a glorious opening in the first half, skying his shot. He did not make the same mistake in the second period, opting to unleash a low shot from the edge of the box and it was enough to beat goalkeeper Michael McGovern.
With debutants Northern Ireland blunt in attack, one goal was all that was required at the Stade de Nice.
- Midfielder Bartosz Kapustka pulled the ball back from the right byline to Milik in the 31st minute. Milik dribbled past two defenders to create a huge opening but blasted over the bar from six yards.
-Eight minutes later, Kapustka had a go after picking up the ball just outside the box. He went for the top left corner but McGovern was equal to his effort.
- Jakub Blaszczykowski's pulled the ball back for Milik in the 51st minute. His low shot from the edge of the area went through Craig Cathcart's legs and squirmed past the McGovern's palm.
- Northern Ireland's first half-chance arrived after 71 minutes. Substitute Conor Washington charged towards goal but a heavy touch allowed goalkeeper Wojciech Szczesny to snuff out the danger.
The talking point
Where will Northern Ireland get their goals from?
Northern Ireland offered little going forwards. Striker Kyle Lafferty was isolated up front as his team-mates hit long balls in hope of finding him. He recorded his side's first shot in the 75th minute and it was a speculative bicycle kick. No player in a green shirt had a touch in Poland's box until the 67th minute.
Northern Ireland came to France without conceding in 271 minutes and this hardworking group can defend. Their plan A seemed to be going for a goal-less draw but there was no clear plan B after going behind.
Man of the Match
Kapustka. The 19-yeard-old only started when winger Kamil Grosicki failed to recover in time from an ankle injury. But the inexperienced international, making just his fifth appearance for his country, was not out of place. He was a constant threat from wide areas and could have had a goal and an assist too.
What the result means
Northern Ireland cannot afford to lose their next game against Ukraine on Thursday, particularly with world champions Germany representing their final group opponents. They overcame huge odds to be in France after becoming the first team seeded fifth or below to top a European Championship qualifying group. But their chances of making it to the knockout stages have suffered a blow. At this point, the continental showpiece appears too big a step up for a squad that has never experienced an international tournament before.
Poland, meanwhile, are that much closer to putting an end to years of underachievement. Germany will provide a stern test in their next match on Thursday. But Poland have already beaten Joachim Low's men in qualifying, and topping Group C will give them a great shot at reaching the quarter-finals.
Milik became the youngest ever scorer for Poland at a European Championship at 22 years and 104 days old.
What they said
Poland midfielder Grzegorz Krychowiak: "We understood that the first match is very difficult, we were prepared for that. The next matches will show that we can be even better and go further."
Northern Ireland skipper Steven Davis: "We have to braver on the ball but it's a real learning curve for us. We always knew it would be difficult but we weren't good enough."