The Mark Purdon and Natalie Rasmussen-trained 5yr-old never gave his rivals a hope of catching him when he produced a stunning 53.3sec last 800m in his front-running victory.
Spankem stopped the clock at 3:14.4 for the 2600m standing start event to equal Classic Cullen's 2010 track record.
The flawless performance again confirmed Purdon's comments earlier this season that Spankem has returned in even better order than he was in during his impressive Miracle Mile-winning 4yr-old season.
The scary news for his New Zealand Cup opponents - and the good news for his fans - is there is more to come, as Spankem builds towards peak fitness for the second Tuesday in November.
''It was a nice run and another step up for him - he went really well,'' Purdon said.
Purdon took no risks when driving Spankem by taking the favourite to the front at the 1600m after he made a fair beginning and settled midfield.
That early position meant the reinsman had to move forward and try to take the front before it was too late.
''I was going to be in a position where I was going to be forced to go,'' Purdon said.
''If I had waited, it was going to be too late in the race and I was probably going to be forced to sit in the death, and he could have over-raced in that situation.''
After a brief tussle for the lead, Spankem controlled the pace before reeling off his stunning finish.
His closing 400m of 26.4sec was even enough to impress his champion trainer-driver.
''He is a very fast horse - he is incredibly fast,'' Purdon said.
Classie Brigade got his manners back in check and boosted his New Zealand Cup hopes when running into second.
The Robert Dunn-trained pacer put his horror beginning in the New Brighton Cup behind him by going straight to the lead in yesterday's feature.
Classie Brigade comfortably held second from Ultimate Sniper, who ran into third after racing three back on the markers.
Purdon confirmed last season's New Zealand Derby winner was still in need of racing to get back to his best after his recovery from a knee operation.
''He was off the scene for such a long time - this time will improve him again.''
Chase Auckland arguably produced the run of the race outside of the winner, even though he missed a top-three placing.
The 5yr-old looked to be in a headstrong mood when he arrived at Oamaru, and he was not on his best behaviour when galloping with a lap to run.
After regaining his composure, Chase Auckland produced an incredible finish to run into fourth placing from last placing before the home turn.
The performance confirmed the pacer's winning debut in open class in the New Brighton Cup was no fluke, and that he was a genuine New Zealand Cup contender.
His chances in the great race may depend on what mood he is in on the day, as he is prone to getting fizzed up on occasions.
''He has got that nature about him, he is just a horse that you have got to catch him in the right mood on the day,'' Purdon said.
A G's White Socks effectively had no winning chance when coming wide on the home bend as Spankem produced his scintillating final sectionals.
Though his effort was sound, the pacer has made his third consecutive poor beginning to a spring campaign.
The first five horses home in the Hannon Memorial are all expected to race in next month's Canterbury Classic at Addington.
