Chris Munce has won his third Grafton Cup but his first as a trainer with First Crush enduring a torrid run to win the Listed race.

Munce won the 2350m Grafton feature twice as a jockey on Count Scenario (1999) and Storm Hill (2005).

Runner-up in the Ipswich and Caloundra Cups, First Crush ($4.20) beat Winkler ($101) by a length on Thursday with favourite Reneged ($3.10) another head third.

Munce admitted it was hard watching as Mark du Plessis navigated a path out wide but all was well in the end.

"I was nearly going to walk back to the horse stalls," Munce told Sky Thoroughbred Central.

"But Mark knew what he was doing. I didn't."

First Crush is raced by Sydney businessman Max Whitby, a long time supporter of Munce, and Jenny Moses, the wife of another former jockey-turned trainer Kevin Moses.

Whitby was a part-owner of Savabeel who Munce rode to win the 2004 Cox Plate.

"I told Max we would win the Grafton Cup and it's terrific to do it for him," Munce said.

"But it's a big team effort. I've got a lot of young kids, a lot of young staff who work tremendously hard."

Du Plessis, a former Zimbabwean who has spent several years in New Zealand, has made Brisbane home for the time being.

"It was a tough run, a terrible run," he said.

"But even though he was wide he was in a beautiful rhythm and luckily he is rock-hard fit."