Co-trainer Brian Johnston thought Zaman had last year's Australian Steeplechase in hand when the gelding cleared the last obstacle.
Zaman had just put his head in front of Maythehorsebemagic but the latter managed to dig deep when it counted to score a brave win for trainer Jarrod McLean and his jockey brother Brad.
"Zaman was going to win but Maythehorsebemagic pulled out a supreme effort and did us that day," said Johnston, who trains Zaman in partnership with his wife Fran Houlahan.
"We may have been a bit soft on our horse in the lead-up to that race but take nothing away from the winner, he's an outstanding horse and he was too good for Zaman on the day."
Johnston and Houlahan will make no excuses for Zaman if the nine-year-old comes up short in Saturday's renewal of the Australian Steeplechase (3400m) at Sandown.
Zaman has steadily built fitness with five races and three barrier trials since late March, including two recent hitouts with champion jumps jockey Steven Pateman aboard.
Johnston said Pateman declared his interest in riding Zaman in the Australian Steeplechase two months ago, travelling to Moe and Cranbourne to partner the gelding in his past two trials.
Zaman finished second to Australian Steeple rival Berlioz in his most recent heat on May 23 but Johnston said the outing convinced him and Houlahan they had their charge ready to perform at his best.
"I reckon he's every bit as good as he was before last year's race," Johnston said.
"In fact, I think he's absolutely peaking at the right moment. The horse is jumping and buzzing and we couldn't be happier with him."
Johnston and Houlahan won the 2010 Australian Steeple with Tarawera, who also won that year's Crisp Steeplechase, and the trainer said Zaman was capable of matching his former stablemate's deeds in time.
Zaman will attempt to become the fourth consecutive son of Zabeel to win the Australian Steeple following Vindicating (2011), Megapixel (2012) and Maythehorsebemagic.