An impressive introduction to city racing from Lonhspresso on Wednesday had jockey Ben Melham predicting the filly could reach the top grade.

Melham rode the Darren Weir-trained three-year-old to victory at Ballarat at her previous start but was even more impressed with the way the daughter of Lonhro put her opposition away on wet ground at Sandown.

Lonhspresso came from back in the field to win by 1-3/4 lengths in the Land Engineering Handicap (1200m), with Melham confident the best is yet to come.

"I think she's a real A-grader," Melham said.

"Knowing how much improvement is in her, I think I'd be shocked if she didn't go pretty close to getting to the top level."

Top apprentice Katelyn Mallyon, meanwhile, notched her first city success since her return from injury.

Mallyon suffered spinal injuries in a race fall last May and spent eight months on the sidelines before making her race return earlier this month.

She guided Bonne Nuit to win the Sportingbet Handicap (1400m).

"It's fantastic being back in the winner's circle," Mallyon said.