The lights may have gone out during trackwork at Caulfield, but they burned more brightly than ever at Flemington thanks to the star colt Pierro.

In his final gallop before Saturday's Group One Caulfield Guineas (1600m), Pierro lit up the track running the final 600m of his 1200m gallop on the course proper in 33.88s and the final 400m in a blistering 21.35s.

But by her standards, trainer Gai Waterhouse was conservative about Pierro's work, declaring it to be "what I expect".

"That's him, he's a super horse," she said.

"He'll show you how good he is again on Saturday."

Pierro is a $1.30 favourite to win the Guineas in which he will be opposed by only seven runners.

And if he wins as expected he is likely to become one of the shortest-priced Cox Plate favourites in history.

As Pierro was lighting up Flemington, Caulfield was plunged into darkness on Tuesday morning by a power outage.

Among the horses on the track at the time was the New Zealander Ocean Park whose trainer Gary Hennessy was unable to watch his horse.

Instead he relied on the report of jockey Glen Boss who painted a happy picture for the trainer.

"Everything this horse does says he's a class act, today was no different," he said.

Ocean Park runs in Saturday's Group One Caulfield Stakes (2000m).