The famous colours of Godolphin have struck on the undercard to the Melbourne Cup at Flemington with Demonstrate.

Sporting the royal blue, which will be represented by five runners in the Melbourne Cup, four-year-old Demonstrate justified his odds-on favouritism in the Lavazza Prontissimo (1400m) with his three-quarters of a length win on Tuesday.

Demonstrate's trainer John O'Shea admitted to some mid-race concerns when the $1.90 favourite ended up back last, but he need not have worried as jockey James McDonald didn't panic and angled the gelding into the clear at the top of the straight.

He sprinted quickly to hit the front at the 200m and defeated Sovereign Nation with a half head to Give Us A Go third.

"That's why we have him on these horses," O'Shea said.

O'Shea will consider backing Demonstrate up in a 1400m open handicap on Saturday.

McDonald said Demonstrate, who had won his past two starts, dwelt slightly at the start and didn't muster much speed but showed a good turn of foot.

"He got back a bit further than I anticipated but he's a nice little horse," McDonald said.