The leading run-scorer in the 2016–17 CSA Provincial One-Day Challenge, Grant Thompson is a veteran all-rounder in South African domestic cricket. His first-class record is quite impressive as compared to other all-rounders in the country; Thomson has seven centuries and 110 wickets in 60 first-class appearances. Grant's first-class debut came during the CSA Provincial Three-Day Challenge wherein he represented Gauteng playing against Boland. Whereas, the all-rounder's List-A debut came against Northern Cape in the Provincial One-Day Challenge at Kimberley; a match that was won by Gauteng.

In February 2018, Grant Thomson was involved in a match winning partnership of 241 with Jurie Snyman while playing for Easterns. Thomson scored 104 in that List A game against North West and helped his team win a close contest by 7 runs as he got the imperative scalp of opening batsman Janneman Malan early in the innings. His tally of 472 runs in 10 matches of CSA Provincial One-Day Challenge (2016-17) remains to be one of his remarkable performances in a tournament.