He made his debut on 20 September 2005, in a League Cup 1–0 defeat at Selhurst Park, replacing Isaac Osbourne on 83 minutes.

A fans' favourite due to his exciting style of play, Thornton scored his first goal for the club on 26 August 2006 against Hull City, but an ankle injury marred what seemed destined to be a successful season,[2] limiting him to just 13 appearances.

[citation needed] On 2 December 2009 he joined Nuneaton Town on a non-contract deal, playing football part-time whilst also touring the West Midlands with his indie three-piece band.

He then made his first league start for the club on 2 March, against Alfreton Town FC, he continued his fine run of goals by opening the scoring, and was later greeted with a standing ovation when he was substituted.

[12] Following a short spell at Rugby Town in 2015–16, Thornton joined Coventry United of the Midlands League Premier for the season 2016–17.

Following his release from Coventry United, Thornton again returned home to Ireland after a short spell teaching yoga in Cape Verde.

After 2 months awaiting clearance from the FA, Thornton made his debut for Harps in a match against local rivals Millmount Celtic, scoring one goal.