Romantic Warrior continued his unprecedented season with a performance for the ages in Sunday’s Group One Yasuda Kinen (1,600m) at Tokyo racecourse.

Sent off favourite to successfully complete his audacious Japanese mission, Romantic Warrior galloped relentlessly through the rain-affected turf to prevail by half a length under superstar jockey James McDonald.

McDonald is rarely lost for words, but even the Kiwi ace struggled to find the superlatives required to describe the Danny Shum Chap-shing-trained six-year-old after he guided him to a fifth consecutive Group One win.

“He’s a champion racehorse and it’s a very proud day for all of us – the whole team – because to showcase him to Japan was something very, very special in such a prestigious race,” McDonald said.

“I’m almost lost for words when I ride this horse because he’s got a big heart and he tries his best all the time.”

Settled in fifth from gate seven, Romantic Warrior travelled powerfully through the early exchanges and turned for home looming ominously on the outside the leaders.

After he was momentarily tight for room at the 400m marker, the son of Acclamation was angled out by McDonald and unleashed down the Tokyo straight.

Romantic Warrior’s stamina kicked in as he hit the front 200m from home, with the galloper charging through the line to complete a titanic treble.

“It looked like a hairy moment for a stride or two but he seemed to cope with it nicely,” McDonald said. “I knew the run would eventually come and it was just a matter of timing it.

“Japan is such a hard jurisdiction to race in. There’s such good horses and great jockeys so it’s an absolute privilege to be here and to be winning such a race is very, very special.”

Despite starting his season in Melbourne for the Group One Turnbull Stakes (2,000m) in October last year, Romantic Warrior brushed aside any doubts of potential fatigue with another brave victory at the top level.

This season he has collected Group One wins in Australia, Hong Kong and now Japan, with the Yasuda Kinen following triumphs in the Cox Plate (2,040m), Hong Kong Cup (2,000m), Gold Cup (2,000m) and QE II Cup (2,000m).

An elated Shum revelled in the win, which moved his galloper to HK$152 million in prize money – HK$15 million short of Golden Sixty’s world record.

“Our team tried really hard, all our team,” Shum said. “James McDonald is world class and he gave him a great ride. He loves Romantic Warrior and Romantic Warrior loves him a lot – he always tries his best for James.”

Romantic Warrior had been given an entry to the Group One Takarazuka Kinen (2,200m) at Kyoto on June 23, but Shum suggested his star would be heading home for a well-deserved break.

“I think the best thing for the horse is to give him a break and let him rest,” Shum said. “He’s not going to race any more this season.”

Elsewhere in the race, it was not to be for Ricky Yiu Poon-fai’s Voyage Bubble, who weakened in the home straight to finish 17th in the 18-runner field.

After Voyage Bubble failed to fire in March’s Group One Dubai Turf (1,800m) at Meydan going left-handed, Zac Purton suggested it was Tokyo’s similar configuration that caused the below-par effort.

“He just didn’t fire in the straight. That’s twice now he’s gone left-handed and he’s performed poorly both times, so I think left-handed is not really suitable for him – get him back going right-handed,” Purton said.