In 2007, Aiken competed on the Nationwide Tour, but made only three cuts, with a best finish of tied 13th in the Price Cutter Charity Championship.

The 2009 season saw Aiken register his maiden top-10 finish on the European Tour, with a tied 4th in the Alfred Dunhill Championship, having led going into the final day after a course record 61 in the third round.

[2] That, along with several other top-10 finishes, including a win in the Platinum Classic, meant Aiken ended the 2008 Sunshine Tour in third place on the Order of Merit.

In May 2011, Aiken won his first title on the European Tour at the Open de España, winning by two strokes from Anders Hansen.

[4] In 2014, Aiken won the Sunshine Tour's Order of Merit, overtaking Daniel van Tonder in the final tournament.