One of the club's longest-serving players, Williamson joined the Blues on a permanent deal in June 2005 following a successful season-long loan.

A trainee with Torquay United, Mike only made 6 senior appearances before the Saints parted with £100,000 for his services.

However his breakthrough at St Marys never came to fruition and after a loan spell back at Torquay, Tony Adams brought him to Adams Park.

In the 2006/07 season, Williamson matured to develop a strong partnership with Will Antwi at the heart of the Blues defence, weighing in with his fair share of goals, and penned a new two year deal that ties him to the club until summer 2009.

Unfortunately, a cruciate knee injury sustained in the defeat to Mansfield Town in February 2007 sidelined him for the rest of the year, but he returned to the side twelve months later and kept captain David McCracken out of the side after a string of fine displays.