Kearney never looked back from that fateful moment in the 38th minute of the opening Test in Durban and emerged as one of the best players of the tour. Four years on he was looking forward to picking up where he left off with the Lions.
But a hamstring injury picked up in the warm-up ahead of Leinster's RaboDirect PRO12 final in Dublin a month ago put his tour in doubt. It has taken until the fifth game on Saturday for him to appear on the team sheet and he has seen Leigh halfpenny, Stuart Hogg and Sean Maitland all play in the No 15 jersey ahead of him.
"If there is one time in four years not to pick up an injury or little niggle it is at the start of a Lions tour. My timing couldn't have been any worse," admitted Kearney.
"I got a scan in Hong Kong and it could easily have gone either way - I could have been getting the first flight back to Dublin or going off to Australia with the lads. It does give you a bit of perspective, especially when you then see a few boys heading home like Cian (Healy) and Gethin (Jenkins).
"Things happen so quickly. Being in that scanning machine was a low point because I had no idea what the results were going to read. I knew it wasn't a serious injury, and that I would get a chance, and I was pretty chuffed with the coaching staff when they gave me the chance to hang on for two weeks without any involvement.
"I took a bit of confidence from that and then you start to feel that luck is on your side. Then you get the chance to put the jersey on again, which is a fantastic feeling, albeit it might be a little bit late. But then there is a lot to happen yet - I'm running perfectly, have no problems at all and I'm even happier than I expected to be."
A fully fit Kearney was always going to be a strong contender for a Test place, but since he last played for the Lions in South Africa Halfpenny has come on the scene and done a great job for Wales, kicking them to Grand Slam glory in 2012 and a successful defence of their RBS 6 Nations title this year, when he was named as the Player of the Tournament.
It was the Welshman who suffered injury agony in South Africa, heading home after only one game because of a nagging thigh injury, but he has already notched 35 points in his two outings to date. He landed 11 out of 11 goalkicks in Perth and hit three out of four In Newcastle, where he also scored a try.
"Leigh Halfpenny has done fantastically well. He found himself in the full back position by chance a little bit. James Hook was there for a while and after Lee Byrne they never really had an established full back, and he stepped in there and made the position his own pretty quickly," admitted Kearney.
"I think he has gone from strength to strength, but I'd like to think I can still push him. Timing hasn't been great, and his 11 from 11 hasn't helped me, but there is a lot to happen on this tour.
"Not just in rugby, but in sport in general, things can happen in a matter of seconds and things can take a U-turn pretty quickly. That's why it is firmly in my mind that there is still a challenge there."