Fahey made his Premier League debut in the opening game of the 2009–10 season at Old Trafford, in the 1–0 defeat against Manchester United. He made 34 appearances in his first Premier League season (18 of which he started), but failed to score all season, as Birmingham finished in ninth place, their highest ever position in the Premier League. In July 2010, Fahey's contract was extended to 2013, in recognition of his having "proved to [McLeish] that he's a Premier League player". He was part of the starting eleven as Birmingham won the 2011 League Cup, defeating favourites Arsenal 2–1 at Wembley Stadium. However, the season would prove to be less successful for both player and club, with Fahey making only 24 appearances in the league (although he did score his first Premier League goal), and Birmingham finishing 18th, and being relegated on the last day of the season, following a 2–1 defeat to Tottenham Hotspur.