O’Neill and Keane have turned Ireland around, says Gary Lim
Manager O'Neill and assistant Keane unlock Ireland's potential
Roy Keane snarls at interviewers, snaps at the slightest provocation and intimidates whenever the opportunity arises.
The 44-year-old was seen by some as the Republic of Ireland's most divisive football figure.
As the assistant to manager Martin O'Neill (near left), Keane (far left) has at times been more trouble than help, like when he gave some of his players a public dressing-down following a loss to Belarus in a friendly earlier this month.
That's why no one was prepared for what happened after the final whistle at the Stade Pierre Mauroy in Lille yesterday morning (Singapore time).
A dramatic late winner by Robbie Brady against Italy sent Ireland into the last 16 of Euro 2016.
A teary-eyed Keane, one of football's most recognisable hard men, embraced O'Neill as the emotions of a thrilling victory got the better of him. This strange, fascinating alliance had done the trick for the Irish.
Not only had they qualified for the Finals against the odds, but they are also now in the knockout stage, readying themselves to take on hosts France on Sunday.
With Brady's 85th-minute goal, the scepticism that has been hovering over the camp since the double appointment of O'Neill and Keane three years ago vanished.
Former Ireland striker Clinton Morrison said: "Even Roy Keane was emotional. For Keane to have tears in his eyes - you know it is special.
"You have to give special credit to Martin O'Neill and Keane, they made a lot of bold changes tonight, and it paid off.
"It's a great achievement, because this group that Ireland were in, nobody gave them a chance to get out of it. They were probably the weakest team in there."
The "good cop, bad cop" partnership O'Neill once so aptly described themselves as has been instrumental in guiding Ireland past the group stage of the European Championship for the first time in history.
Against the Italians, who were already assured of top spot in the Group of Death before yesterday's clash, O'Neill went for the jugular.
The 64-year-old may not have the most talented group, but what he has is a team full of gutsy players.
The 3-0 drubbing by the Belgians in their previous game had left Ireland requiring a win against Italy.
O'Neill decided that he needed energy and physical presence against technically superior opponents, so he turned to a younger lot.
He dropped the experienced trio of John O'Shea, 35, Wes Hoolahan, 34, and Glenn Whelan, 32 - who boast a combined 219 caps - to the bench.
In came the relatively raw Richard Keogh, Shane Duffy and James McClean, who combined for 161 caps fewer.
A fresher Irish side boosted by more power and pace took the game to Italy.
But the former Celtic, Leicester City and Aston Villa manager's courage hasn't always been unwavering.
A home draw with Scotland last year during their Euro 2016 qualifying campaign, which saw them win just two out of their first six matches, had knocked the stuffing out of O'Neill.
If not for Keane, 44, Ireland probably wouldn't have been in France in the first place.
O'Neill recently recalled: "He (Keane) was very good. He said, 'This isn't over'. He was buoyant. He reminded me you can't get dispirited."
It took 14 years for Keane to fully shake off the pariah's tag, one he earned at the 2002 World Cup for walking out on the team during their training camp. Now, together with O'Neill, the pair are rewriting the country's football history.
Ireland won't be feeling the pressure against France, who have much higher expectations to manage.
With O'Neill and Keane behind them, the Green Army will be fearing no one.
REP OF IRELAND 1
(Robbie Brady 85)