Manager Michael O'Neill expressed his pride after seeing his bold gamble pay dividends in Lyon as a much-changed Northern Ireland side kept their Euro 2016 hopes alive with a 2-0 victory over Ukraine.
A 1-0 defeat to Poland last Sunday had left Northern Ireland teetering on the brink of elimination but four days later and O'Neill responded by changing five players in his starting line-up, dropping the likes of Kyle Lafferty, Paddy McNair and Chris Baird and reverting to a 4-5-1 formation.
Those that came in stepped up, though, and goals from Gareth McAuley and substitute Niall McGinn ensured a first victory at the European Championship finals, and a first at a major tournament in 34 years, meaning a last-16 berth could be sealed in Paris against world champions Germany next Tuesday.
"I'm just delighted for the players and the work they've put in," O'Neill said.
"They were down for longer than I wanted against Poland yet that reaction was fantastic. It showed me how much they were hurting. Individually they were disappointed with some of the performances in the team but when you get that reaction, then you can't ask for any more.
"As I said to the players, it was probably the proudest I have felt, certainly in the dugout and probably throughout my football career. As a manager you can be tactical, you can be organised and you can ask for different things, but when you get a performance like that, which is just pure commitment, pure heart, there's nothing more you can ask for."
The time spent on the Poland post-mortem had led to some radical tinkering for O'Neill, who knew his country's fate would rest on his roll of the dice.
"We did so much work leading into the first game, the work we did was of a really high quality, the players took it on board," he added.
"Whether it was a combination of Poland being very good or us being below par you do question yourself a little bit.
"I just felt having watched it back from the different camera angles we needed to get more running power into our team in the middle of the park and in the wide areas.
"We had always planned to play four at the back because of Ukraine's threat from the wide areas with (Andriy) Yarmolenko and (Yevhen) Konoplyanka, we'd be more suited to the 4-5-1 we played in qualifying for this game. The two boys at full back...how they dealt with the two wide players was magnificent.
"There was big decisions that had to be made, it's never easy changing half your team and it was difficult to leave lads out, it's not as if they didn't give me everything on Sunday. I had to make those decisions and thankfully they paid off."
McAuley spoke of the satisfaction Northern Ireland had taken from overcoming widespread doubts to defeat Ukraine.
McAuley said: "Nobody has given us a chance. Lots of people said we wouldn't get a point. We weren't at it against Poland - to our standards, the intensity we wanted to play at - but tonight was a lot better. We're delighted for every one of these people that's come to support us.
"It's special (to score), it'll sink in probably over the next few days. The team performance was pleasing, the reaction from getting beaten against Poland...We've got a tough game to look forward to now, and we've got something to play for: that's what we wanted."
Ukraine manager Mykhaylo Fomenko fumed about his team's inability to defend set-pieces, with McAuley breaking the deadlock by heading home from Oliver Norwood's free-kick early in the second half.
"The players were not united today," he said.
"They didn't fulfil the requirements, especially the formation and how they carried out the set-pieces.
"Nothing surprised us, we were expecting this level of football. I think that of the 16 goals scored by them in the qualification rounds, nine of them were from set-pieces so we understood that they can score impressive goals from set-pieces and we were preparing for this kind of football.
"The major mistakes, I think we saw them today on the pitch. I think we weren't prepared enough in psychological matters.
"Perhaps our players over-estimated the opponent and under-estimated the efforts they needed to deploy to get the victory. We allowed the opponent to play its own football, that's why we lost."