As a 17-year-old with Crumlin United, he was good enough to earn a trial with Preston North End, but any hopes he had of making a career across the water were dashed when he suffered a cruciate ligament injury on his return to Dublin.
On his return from Poland John McDonnell (footballer) invited him to train with St Pats and he was signed shortly after.
O'Connor opened the scoring in the league cup against UCD and later captained his side for the first time when Ger O'Brien was taken off after 66 minutes.
[18] O'Connor had a great impact off the bench in the Dublin derby against Bohemians when he put in a world class cross for Christy Fagan to head home in the 4th minute of injury time in a 2–1 win at Richmond Park.
[19] Just four days later and he was action in another Dublin derby, this time at home to his old club Shamrock Rovers in the 2012 League of Ireland Cup quarter-final.
The game went to extra time and penalties and O'Connor took Pats' first and scored on Reyaad Pieterse in the Rovers goal.
[21] O'Connor scored in the FAI Cup final at Lansdowne Road at the same end against the same opposition in the 2012 version as Pats lost out once again.
He continued his run in the team into the 2014 season, playing in twenty-five league games and scoring four goals as Rovers finished fourth.