Gareth Bale's Wales stumbled into the Euro 2016 quarter-finals on Saturday, beating fighting Northern Ireland 1-0 from an own goal by Gareth McAuley.
McAuley stuck out his leg out in an attempt to clear Bale's sharp low cross from the left wing in the 75th minute, but hit the ball into his own net.
It was a lucky victory for Wales who were not as creative as in their group games and rarely threatened apart from a free-kick by Bale against a firm Northern Ireland team whose best chance in the last 16 game was an early effort from Stuart Dallas.
But they matched their best ever international result, from the 1958 World Cup, as they clinched a quarter-final berth - on Friday in Lille against Hungary or Belgium.
"It was an ugly win for us but who cares," Wales manager Chris Coleman said. "Northern Ireland played well, we never played as good as we could.
"It's an unbelievable feeling. We wanted to come to the tournament and do the nation proud. You don't know how far you can go because you can have luck or bad luck. Today we had a bit of good luck and Northern Ireland bad luck."
Man-of-the-match Bale said: "It is fantastic. Northern Ireland shut up shop but we knew we had a moment of quality in us. We made them tired, we knoew we could grind them down and force them into a mistake."
Northern Ireland manager Michael O'Neill said: "It is a very cruel way to lose. We didn't deserve to lose in this nature. It was a very tight game and we had the better of that to be honest."
Wales manager Chris Coleman made no changes to his starting 11 that had impressively beaten Russia 3-0 in the last group game while Northern Ireland forward Kyle Lafferty returned into the starting line-up in place of Conor Washington.
While both sets of fans were at their very best and in full voice the started teams nervously into the first meeting of two home nation teams in the knockout stages of a major tournament.
Northern Ireland pressed high whenever possible and successfully contained Bale and Aaron Ramsey. They also got a first change in the 10th from Stuart Dallas whose left angle shot was palmed away by Wayne Hennessay after a fast counter-attacking move.
Wales gained a little more control, with Bale often found on the left wing and Ramsey dropping back.
But they lacked ideas to break down a firm Northern Ireland defence although Ramsey first failed to flick in Bale's curling cross, and was then ruled offside when he tapped in off a header by Sam Vokes which itself looked promising.
Hennessey tipped Jamie Ward's distance effort over the bar on the other and the first half trickled out with Northern Ireland facing no major danger as they had in Monday's 1-0 defeat against Germany.
The quality of play remained modest at best after the restart with Vokes heading wide in the 50th.
It took a set piece for the Real Madrid star Bale to threaten a first time. But Northern Ireland goalkeeper Michael McGovern kept up his great form from the Germany game when he dove to his left to keep out Bale's 25m free-kick in the 54th in what was Wales' only shot on target.
Wales eventually broke the deadlock somewhat out of the blue with 15 minutes left from McAuley's misfortune, with Wales substitute Hal Robson-Kanu lurking right behind him on Bale's cross.
Northern Ireland were unable to fight back as the Wales players and fans could eventually celebrate victory, while the Northern Ireland fans also bid their team a rousing farewell from the Euros.
"Not many people gave us a chance of doing anything at the tournament and we came close to be last eight. The pride and commitment to play for the country was a fantastic experience for everyone," O'Neill said.