It was a case of 'job done' for Vauban at Naas in the early hours of Tuesday morning, Australian time, when the Melbourne Cup favourite successfully passed the ballot for Australia's most famous race.

The Willie Mullins-trained gelding was a comfortable winner of the Group 3 Ballyroan Stakes (2398m) at the Irish track.

A runaway winner at Royal Ascot at his previous start, Vauban needed a top-three finish to satisfy the first ballot clause for the Melbourne Cup which Mullins' assistant trainer David Casey, who will travel to Melbourne with Vauban, said was the purpose of the exercise.

"It ticked a box, which we were here for today, to get placed to qualify for the Melbourne Cup," Casey told Racing TV.

"I think there is plenty of improvement in him. He had a little break after Ascot and was ready to start back today."

Vauban, who settled just behind the leaders before cruising to the front around 550m from home and holding a margin of more than a length for the last 400m, scored by 1-1/2 lengths from Valiant King with Peking Opera 4-1/2 lengths back third.

Ryan Moore rode Vauban at Royal Ascot and is the leading contender for the Melbourne Cup provided Vauban is allocated enough weight, but Colin Keane was in the saddle at Naas and the Irish jockey declared his availability for the ride at Flemington.

"I'm sure I could make myself available if needs be," Keane said.

"I'm not sure (if he's a Melbourne Cup horse) because I've never been there, but he ticks a lot of boxes; he stays well, he's very uncomplicated, he's won on quicker ground at Ascot and he handled slow ground here today, so you'd like to think he ticks a lot boxes."

The Ballyroan Stakes was the first Group success on the flat for Vauban, a multiple Grade 1 hurdle winner, and Casey said Mullins' attention would now turn to determining whether to give the son of Galiway another start in the UK or have his next run at Flemington.