Wesselingh turned professional in 1985 but opted for a career as a club professional rather than attempting a touring career. Upon turning 50, Wesselingh opted to join the on the European Senior Tour after coming through Qualifying School.
 
He was runner-up in his first tournament, and claimed his first win three events later. Wesselingh went on to greater success in 2013, winning five events including the MCB Tour Championship – Mauritius held at Constance Belle Mare Plage, earning him the number one spot for the tours Order of Merit for the 2013 season.