Decorated jockey Robert Thompson has produced a ride for the ages to win the $150,000 Townsville Cup for the second time.

Two decades after scoring on Once Upon A Crime, Thompson threaded his way through the field to land The Harrovian ($6) a narrow winner.

Thompson is a Hall of Fame jockey who rides out the lower NSW Hunter Valley and he is a regular visitor to north Queensland's racing carnivals.

The veteran has won more than 4400 races in a career that spans almost five decades.

He used all of that experience after The Harrovian settled worse than midfield in a 2000m race that was run at a muddling tempo.

But instead of scouting wide on the former Victorian, Thompson took his chances when he decided to save ground.

It was a winning move as The Harrovian made his bid between horses to edge out the favourite Unbiased ($3.10).

Unbiased is part-owned by northern NSW trainer Cody Morgan who had a metropolitan double in Sydney when Pat's Nipper and Ligulate won at Rosehill.

The Harrovian is now trained out of Cairns.

Since stepping out for his new Queensland stable in March, The Harrovian has had seven starts for five wins.