Less than two minutes into the 2001 Ulster quarter-final, Kieran McGeeney was off balance as he gathered a loose ball near the endline and Stephen O'Neill swooped on the opportunity like a hawk.
McGeeney hadn't time to assume the brace position and O'Neill nailed him. The goal Tyrone had scored immediately from the throw-in was a far more significant factor but the sound and implication of a rookie flooring Armagh's talisman almost exceeded the goal's value in terms of the confidence it transmitted throughout Tyrone's young side.
At the end of the following year, the 2001 All Stars team played the 2002 side in the tour match in San Diego. It was a meaningless funfair of a match but the only two serious collisions in the game involved McGeeney and O'Neill. Easing up would run against McGeeney's grain, and O'Neill wasn't able to contain himself either because Armagh were All-Ireland champions and McGeeney remained the emblem of the citadel Tyrone were still desperately trying to sack.
When Tyrone travelled to Donegal for a training day two weeks before the 2003 All-Ireland final, a flipchart outlining the challenge posed by Armagh was presented before the players in the Abbey Hotel. At the top of that list was one key point that Tyrone sought to address: 'McGeeney's influence – swarm!'
Tyrone forensically focused on numerous areas of Armagh's strengths but they were all made fully aware of how diluting McGeeney's authority and impact was one of the powerful means of beating them.
The Ulster rivals met in seven monumental championship matches between 2001 and 2005 and when Tyrone finally broke Armagh, cracking their strongest link ultimately helped break the chain that had bound them together. Armagh never recovered from their 2005 All-Ireland semi-final defeat. It was even harder to stomach when most of the squad felt it was self-inflicted.
Armagh had Tyrone on the ropes and failed to knock them to the canvas but McGeeney's substitution with seven minutes remaining was one of the game's defining moments. It flattened Armagh and elevated Tyrone's spirits, who scored the last three points to win by one. "When Kieran did leave the field, it definitely gave us a lift," said Sean Cavanagh afterwards.
That moment had a profound impact on McGeeney and certainly put a strain on his relationship with certain sections of the Armagh management. He retired at the end of 2007, which radically altered the path of his sporting career and led him into management with Kildare just one month later.
As a young manager, McGeeney had to learn the same way he did as a young player. He got his beatings, and some of those in the early days were at the hands of Tyrone. When Tyrone beat Armagh in 1994, an error from McGeeney had a huge impact on the outcome. He totally missed an innocuous bounce from an Adrian Morris free, which left Plunkett Donaghy in the clear to score the goal to put Tyrone out of reach. When Tyrone defeated Armagh again in 1997, it was Armagh's fourth successive championship defeat since 1994.
The sides traded wins in 2000 and 2001 before they met again in 2002 in two of the biggest games Armagh ever played. On both days, McGeeney set the tone. Armagh were hanging on in the dying moments of the replayed Ulster quarter-final. As goalkeeper Benny Tierney was preparing to take a kick-out, McGeeney just pointed to his chest and Tierney kicked it straight to him. In the drawn game, McGeeney dived about three feet to get in a block on Seamus McCallan to prevent an equalising point.
McGeeney was never motivated by regrets, but one of his biggest was how Armagh toned down their aggression levels for the 2003 All-Ireland final. In tackle situations, they were accused that summer of following through with the hand into their opponents' faces, but it was a relatively common practice at that time, especially in Ulster.
Most of Armagh's force was imparted legitimately but McGeeney's style had come under intense scrutiny from media pundits and referees that summer. In the All-Ireland final, some team-mates felt that McGeeney's play was restricted by that scrutiny.
Changing their style of play and giving Tyrone too much time on the ball in that final still grates on Armagh, but defeat in the 2005 All-Ireland semi-final was the deepest cut of all. McGeeney's substitution exacerbated that pain. Although he played wing-back, he had the experience and intelligence to shut off the centre in those closing minutes. In all the Armagh-Tyrone games between 2002 and 2005, those last seven minutes was the only time that Cavanagh really attacked down the middle of the Armagh defence.
The decision still haunts that squad. John McEntee once said that "it was a huge psychological blow for us and a huge psychological boost for Tyrone". Joe Kernan, though, first publicly defended the decision in 2009 in Finbarr McCarthy's book 'Bainisteoir'.
"It was a huge call but that's my job," said Kernan. "I don't know if Kieran is still annoyed with being taken off. Maybe he is but he never said it to me. But the facts are simple.
Our stats man told us Kieran had not touched the ball in 17 minutes. We made the change hoping to freshen things up and to get on the ball. That was our call then and we stand over the decision. But that substitution was not the winning and losing of the game."
The terror and helplessness on McGeeney's face was clearly visible from the TV pictures as Peter Canavan lined up the match-winning free-kick – some of McGeeney's most defining images are from games with Tyrone; he cut a disconsolate figure in the tunnel after the 2003 All-Ireland final but he remained for the presentation out of respect for Canavan and primarily, because he wanted to remember how low he felt and to store that feeling for the future.
McGeeney never played against Tyrone in the championship afterwards but he faced them as a manager for the first time in the 2009 All-Ireland quarter-final, which Tyrone narrowly won.
Tyrone have also won three of their last four league meetings but the one game that Kildare did win – last year's Division 2 league final – was the biggest match of the four. Furthermore, it ended a 12-game unbeaten Tyrone run.
McGeeney's character wouldn't allow him to treat a game against Tyrone any differently than he would prepare for any other opposition. But McGeeney always saw Tyrone as the ultimate challenge.
"Going up against Tyrone was pitting yourself against the best and that's the one thing McGeeney loved because he always wanted to prove that he was better than them," Oisin McConville once remarked.
"Anytime we played Tyrone we were always hyped up to the gills – you would eat wire to get out on to the pitch. And anytime we were that driven, it was McGeeney who was really driving us."
Sunday is a chance for McGeeney to take Kildare back to centre stage. Tyrone stand in their way but nobody knows the Tyrone psyche and character better than McGeeney.