Long-priced winners are rare for the Danny O'Brien stable but, even so, Grinzinger Bishop's knockout win at $71 at Flemington on Saturday did not come as a shock for connections.

O'Brien, who also won the opening Flemington event with stayer Saracen Knight on Saturday, explained after Grinzinger Bishop's boilover win that the two-year-old son of Almanzor had trialled well before a moderate debut where he struggled on a very wet surface at Geelong.

"He went to Geelong with some expectation - he's a horse that's always trialled well and he's a horse that's always impressed us," O'Brien said.

"The Geelong track was really wet, he got back on that Soft track and basically barrier-trialled, he was rolling in his box the next morning.

"We put a set of blinkers on him on Tuesday morning, really the only hope of getting a half decent surface was to run him in town.

I spoke to (owner) John (Wheeler) earlier in the week and said 'We're going to run him, we think he's a lot better than what he did at Geelong'."

Grinzinger Bishop may swiftly go from an unwanted winner over winter to a Gr.1 Victoria Derby (2500m) hopeful, according to O'Brien.

"He's a horse we're hoping might be a Derby horse in the spring - he stayed on there super today," he said.

Beau Mertens rode Grinzinger Bishop and he explained later that O'Brien had filled him with some confidence as he legged him aboard.

"Danny informed me he's not here for no reason, he just went around at Geelong, Heavy track, inexperience," he said.

"He seemed to take a lot from that run because he jumped really well, put himself into the race and travelled really kindly for me."

Grinzinger Bishop credited Cambridge Stud’s exciting shuttle stallion Almanzor with his sixth individual first-crop Southern Hemisphere winner with his tally including the Karaka Million (1200m) hero and Gr.1 Sistema Stakes (1200m) runner-up Dynastic.

Grinzinger Bishop’s success has earned him a spot in the Taj Rossi Series Final over 1600 metres at Flemington in a fortnight’s time.

“We may press on if he does well and that would still give us ample time to get him ready for the back end of the spring,” O’Brien said.

Co-bred by the Dowager Duchess of Bedford, Grinzinger Bishop was purchased by Victorian owner John Wheeler out of Brighthill Farm’s draft at Karaka for $55,000.

He is a son of the Listed Trevor Eagle Memorial Stakes winner and multiple Group placegetter Tavy, a Tavistock mare whose grand-dam Good Faith won the Gr.1 Ellerslie Sires’ Produce Stakes (1200m).