"He could be the best of the New Zealand Cup winners I have driven," May said.
"He is speedy and tough."
May has also won the race with Inky Lord (1989), Iraklis (1997) and Mainland Banner (2005).
"Inky Lord and Iraklis were more sit-and-sprint horses and Mainland Banner was speedy," May said.
The 51-year-old Methven reinsman is now the second-most successful driver in the race, along with Jimmy Bryce and Peter Wolfenden, behind Cecil Devine, who won the race six times.
"We just can't praise Ricky enough for the job he does with our horses," Brendon Hill, the Ohoka trainer of Monkey King, said.
Robert Famularo, the Auckland owner of Monkey King through Cavalla Bloodstock Ltd, said May was a key player in the successful operation.
Hill (35) took over training for Famularo when Steven Reid opted to join Graeme Rogerson in a training partnership last season.
It was not a major change as Hill had worked for Reid as a junior driver and also in managing a stable for the Famularo horses in Canterbury.
Monkey King was narrowly beaten in the New Zealand Cup by Flashing Red two years ago and he finished last in 2008 when off colour.
The win yesterday was his 29th in 63 starts and the $538,860 first prize took his earnings to $1,741,845.
Hill said he was relaxed leading up to the race as Monkey King had done everything asked of him this season.
"The standing start was a wee bit of a concern but Ricky got him away brilliantly from the unruly position."
The occasion was emotional for Famularo, an Auckland businessman with his main interests in building materials.
"I cried when the national anthem was played and again at the end of the race," he said.
Racing horses is a business and challenge to Famularo.
He paid $20,000 for Monkey King at the premier yearling sale when the son of Sands A Flyin-Tuapeka Vale was offered by Christchurch breeders Mrs J M Sharples, Mrs L K Lewis and Mr M J Lewis.
Monkey King had been selected by Reid.
Tuapeka Vale is by Smooth Fella from from Sakuntala.
Iraklis was by Vance Hanover from Tuapeka Star, by Knowng Bret from Sakuntala..
Tennis Ball, a well-performed stablemate of Monkey King, was scratched yesterday from the junior free-for-all when slightly tender after pulling a shoe.
Baileys Dream, another well-performed pacer in the stable, is back jogging after having cartilage removed from a knee.
He is being aimed at the Auckland Cup.
Monkey King is expected to contest the New Zealand FFA on Friday.
Monkey King came from back in the field and wide out to win by a neck from Bettor's Strike, whom driver Dexter Dunn considered unlucky.
There was a length to Smoken Up, who attempted to lead from the 1900m.
The time was 3.57.3, 0.9sec outside the world record set last year by Changeover, who finished fifth yesterday.
The last 800m was run in 56.9 and the 400 in 27.9.
