In-form Lite'n In My Veins has passed a distance test with a strong win at Moonee Valley, continuing a successful preparation for the former West Australian galloper.

The Ciaron Maher-trained Lite'n In My Veins was stepping up beyond 1600m for just the second time in his career in Saturday's Dominant Martin Ralston Cup (2040m), having been unplaced last year in Perth in his only attempt at 2000m.

With apprentice Liam Riordan aboard on Saturday, Lite'n In My Veins ($7) gradually worked forward from a wide gate before eventually slotting in one off the fence in fourth with a strong tempo up front.

Riordan, who only recently joined the Maher stable, then got going on the gelding to hit the front before the home turn and they went on to defeat Mr Nordic Hero ($5) by three-quarters of a length, with 1-1/4-lengths to Magnapal ($12) third.

It was the gelding's fourth win from his past five starts.

"There was a little question out to the 2000 metres but I think the last time he went out to 2000 he was sort of at the end of a prep," Maher said.

"He's just racing in great form.

"We thought maybe next year he might be a Doomben Cup-type horse so it was a challenge. We wanted to see if he could do it and obviously he's done it here and done it well."

Maher said he had Riordan watch replays of his former stayer Mr O'Ceirin's win in the 2013 Grafton Cup.

He believed Lite'n In My Veins would benefit from a ride similar to Mr O'Ceirin's that day, and he described Riordan's ride as "brilliant".

Stewards, however, took issue with Riordan's actions in the final five strides of the race and fined the apprentice $500 for not riding the horse out right to the line.

Riordan also incurred an 11-meeting suspension for careless riding aboard another Maher-trained runner, Akavoroun, who finished third in Saturday's Kate O'Sullivan Mile.