Messara rated Ortensia's fourth placing behind runaway winner Mayson in the July Cup as "up there with her best performances".
The Newmarket track surface was extremely heavy and jockey William Buick was forced to ride Ortensia closer to the speed as it was absolutely impossible to make ground from back in the field.
Ortensia, who started at 9/1 with English bookies on track, loomed up to challenge about 200m out but could not unleash her trademark finishing sprint in the wet conditions before holding on for a game fourth.
"She didn't handle the track at all, William got off and said she didn't like it one bit," Messara said.
"The track was as wet as you would find back home - it has been raining that much, particularly this morning, I considered coming here in an Ark and applying for a late gear change of snorkel and scuba mask.
"The last furlong, up that steep hill in those very trying, testing conditions, was tough but I thought it was a massive effort by her to run fourth."
Ortensia pulled up surprisingly well after the race, giving Messara more reason to press on to the Nunthorpe Stakes.
But the trainer concedes he has respect for the English sprinters.
"There are some great sprinters over here. They have a massive pool of horses so you would expect there to be some good ones among them.
"Our sprinters have a better turn of foot but the English sprinters tend to mix speed and stamina and go a long way from home. It's a different style of racing here."
The game effort of Ortensia was in stark contrast to Sepoy's inglorious run where he beat only one home.
Sepoy, winner of the Golden Slipper and Blue Diamond last year, was a shadow of the crack sprinting colt we saw when trained by Peter Snowden at Warwick Farm.
The Godolphin stable confirmed that Sepoy went directly into quarantine on Sunday and will return to Australia, where he will stand at Darley Stud in NSW's Hunter Valley during the spring breeding season.
