Star Tasmanian galloper Geegees Blackflash has added another amazing chapter to his racing story in claiming his second Group Three Hobart Cup.

Running in the Cup for the fifth year in a row, Geegees Blackflash had topweight of 59kg and gave his major rivals a start before weaving his way through the field.

He kept finding something extra in the straight to narrowly deny Genuine Lad.

The victory in Monday's $225,000 feature prompted his owner-breeder Paul Geard to declare it his proudest day in racing and trainer John Luttrell labelled the win an unbelievable effort.

"What he did today was unbelievable to come from last and beat those horses," Luttrell said.

"He's all guts. He just needed a bit of a luck and he just kept coming.

"What a horse. He's a champion, isn't he."

Eight-year-old Geegees Blackflash is the only horse to earn $1 million prize money racing exclusively in Tasmania and he became the first horse since Brallos in 1976-77 to win two Hobart Cups.

His first success in the Hobart Cup (2400m) came in 2012 and he had been placed in the past two renewals.

The win also capped a huge day for Paul and Elizabeth Geard, with Tasmanian racing's biggest owners and breeders also claiming stakes wins with the gelding's half-sister Geegees Goldengirl in the Listed Strutt Stakes and their two-year-old Gee Gees Top Notch won the Listed Elwick Stakes.

Geegees Blackflash has won 22 of his 63 starts including the 2010 Tasmanian Derby and the 2013 Launceston Cup.

He denied Genuine Lad by a half neck on Monday with Banca Mo another 3-1/2 lengths away third.

Jockey Anthony Darmanin said Genuine Lad was brave in defeat after a three-wide run.

The best of the interstate finishers was Pelicano who came in fifth, leaving trainer Tony McEvoy disappointed with the stayer's performance.