Northern Ireland reached their first major football tournament in 30 years and their neighbours south of the border beat world champions Germany to take a big step towards joining them at Euro 2016 in a memorable night for Irish football.
Northern Ireland have never been to a European Championship in over 50 years but the Group F pace-setters made sure of their place in France next year in emphatic style with a deserved 3-1 home victory over Greece at a raucous Windsor Park in Belfast.
The atmosphere was just as wild in Dublin's Aviva Stadium as Ireland secured at least a playoff spot with a shock 1-0 win, raising the prospect that both teams - split by a 500 kilometre winding border and a complex history - could qualify for the same tournament for the first time.
"Anyone for France next year?" Northern Ireland's four-times golf major winner Rory McIlory, who sat next to world boxing champion Carl Frampton at Windsor Park, tweeted after the game.
"Unbelievable result for the Republic too! Great night for the island of Ireland, north and south. Hopefully see both teams in France next year," said McIlroy, who will represent Ireland at next year's Olympic Games after agonising over whether or not to opt for Britain, which controls Northern Ireland.
Northern Ireland's first and deputy first ministers, Peter Robinson and Martin McGuinness, also took to Twitter to congratulate the team who last qualified for a major tournament at the 1986 World Cup.
They reached the latter stages four years earlier when they were captained by current Ireland manager Martin O'Neill and memorably beat hosts Spain.
Ireland, whose Prime Minister Enda Kenny described the Group D result as "stunning", only qualified for a major tournament for the first time in 1988 and have reached four more since, most recently the 2012 European Championship.
Ireland can seal automatic qualification with a victory in Poland on Sunday -- the same day Ireland's rugby players, who unlike in soccer play as part of an all-island team, take on France in a crucial Rugby World Cup game.
A similar approach for soccer could just produce an unbeatable team, according to Sinn Fein leader Gerry Adams, whose party has members of parliament on both sides of the border and want a united Ireland.
"The Island of Ireland soccer teams won tonight. Well done to both teams. Time for one united team. A world beater!" Adams said on Twitter.