Trainer Mike Moroney admits Mr Marathon Man and Buffalo River are still works in progress but he has loftier ambitions for the pair after they raced to strong wins at Sandown.

Five-year-old Mr Marathon Man, a Listed winner in France, notched his first Australian victory at his third local appearance in Saturday's Ladbrokes Back Yourself Handicap (1600m).

Three-year-old Buffalo River then made it two wins from as many Australian starts in the Ladbrokes Multiverse Handicap (1600m).

Under the urgings of champion jockey Damien Oliver, Mr Marathon Man ($11) chased down favourite Waging War in the soft conditions to score by a nose and Moroney plans to race the import sparingly through winter in a bid to get him to the spring carnival.

"We think he is Group class," Moroney said.

"It's just a matter of where he does fit in.

"We knew he had ability but it's just been hard to get him to do things right.

"His real form is at 1800 to 2000 metres so we're hoping to get him there."

The Listed Winter Championship Series Final (1600m) at Flemington on July 6 looms as Mr Marathon Man's likely next start.

His victory on Saturday was the middle leg of a winning treble for champion jockey Damien Oliver who also won on Buffalo River and the Patrick Payne-trained Street Sheik.

Buffalo River, who won one of his four starts in England when trained by John Gosden, scored a frontrunning win in a benchmark 70 at Ballarat last month in his Australian debut.

The $1.95 favourite was able to take a trail behind Asgard Massif before taking over in the straight and drawing clear to beat him by 3-1/2 lengths, with Our Campana another three lengths away third.

"I thought it was a really good win today," Moroney said.

"I'll just have to have a think about where to go with him now because he impressed me today.

"Both our two winners were really good efforts."

John Allen, meanwhile, was suspended for 10 meetings for weighing in 1kg over on El Vincitore, who finished second to Tysonic in Saturday's sixth race.

Allen already has two careless riding suspensions to serve - incurred at Doomben and Pakenham - meaning he will be out of the saddle from after Sunday until July 19.