Chris Waller revealed another dimension to the talents that makes him Australia's most successful trainer - he gets it right even when he thinks he's got it wrong.

The latest revelation was delivered with the help of Epsom Handicap winner Boban and jockey Glyn Schofield as they made the Group Three Moonga Stakes (1400m) - the horse's fourth win on end.

"At the 600 (metres) I thought I'd made the wrong decision bringing him back from a tough Randwick mile to 1400 metres here," Waller said.

"It was good to see him warming up at the 300-metre mark.

"But even then he had to maintain it to win."

Boban drew the outside gate in the 12-horse field and had no choice but to go back to last.

With the entire field still in front of him entering the straight his prospects looked grim, but Schofield weaved a path and in the final 100m Boban started stretching out as he had at Randwick two weeks ago.

A supremely confident Schofield needed only to sit quietly as Boban, the $3.60 favourite, claimed the lead under his own steam and scored by a short head from Strawberry Boy ($8.50) with 1-1/2 lengths to Galah ($14) in third.

For Waller the win demonstrated Boban's versatility and potential.

But it didn't make his next assignment any more obvious.

"I'd thought of trying to win another Group One with him the Emirates Stakes," he said.

"But he's going to get a lot of weight now, that's my concern."

"If the Emirates isn't his race, he'll certainly get plenty of chances throughout his career."