He first came to prominence in the 2010 UK Open when he impressively defeated Stuart Monaghan in the First Round by 6 legs to 0. He then defeated Mark Frost and Peter Wright to reach the fourth round, where he played world number 3 James Wade on the main board and lost 9 legs to 3.

O'Connor qualified for the 2010 World Grand Prix, where he lost to Barrie Bates in the first round by 2 sets to 0.

O'Connor along with Mick McGowan represented Ireland at the inaugural PDC World Cup of Darts in 2010. The pair defeated Slovakia in the first round 6 legs to 3. However, they were narrowly beaten 6 legs to 5 in the second round to the Australian duo of Simon Whitlock and Paul Nicholson, who were number 4 and 16 in the world rankings respectively.

He played in his second World Cup for Ireland in 2012, again paired with McGowan and, as in 2010, they reached the second round this time by defeating Malaysia 5–2. They played the same Australian pair as in 2010 next and were whitewashed 0–4. The next week he reached the quarter-finals of the first UK Open Qualifier, but was defeated by Kevin Painter 4–6. This would later prove to be O'Connor's deepest run in a tournament in 2012. During the year he qualified for three of the five European Tour events. He was knocked out in the first round of the first two, but at the German Darts Masters he saw off Painter 6–5, before losing 3–6 to Wayne Jones. O'Connor was one of the two Irish qualifiers for the World Grand Prix and missed a dart for the match in the first round against Vincent van der Voort, losing 1–2 in sets.

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Wikipedia