The pounds 97,489 prize swept the Godolphin trainer Saeed Bin Suroor back to the top of the table - his lead over Cecil now stands at pounds 32,000 - in what has been an absorbing rivalry, and one that will now surely last until the end of the turf season at Folkestone two weeks tomorrow. Both trainers - in Toronto on Breeders' Cup duty yesterday - have vowed not to carry on on the all-weather.
With the star jockeys also at Woodbine, Gary Hind, called off the substitutes' bench to partner Medaaly, grabbed his opportunity with both hands and was rewarded with the first Group One winner of his nine-year career.
The grey colt, a 14-1 outsider, got the better of a dour struggle with Poteen in the final quarter of a mile, regaining the lead from his less experienced rival inside the final furlong to score by half a length.
The favourite Benny The Dip, who looked unsettled beforehand, stayed on into third place with Cecil's candidate Besiege fourth.
Hind, 28, is in his first season as stable jockey to Peter Harris, but has strong links with Sheikh Mohammed. He has ridden in Dubai for the last three winters and rides out regularly for one of the Sheikh's Newmarket trainers, John Gosden.
He said: "I was a bit worried early, because Medaaly wasn't really travelling. But in the straight he came back on the bridle and used his experience to battle back past the other horse.
"When he was beaten last time the wrong tactics were used, and the team was quietly confident. They weren't just going to lie down and let the title slip away, and I am proud and happy to have played my part in what could be a vital race for them."
Cecil, going for his 11th title, went into the day a shade over pounds 60,000 ahead and increased his lead with placed efforts at Newbury, where Bin Suroor's runners drew a blank, from Questonia, Dragonada and Eva Luna, third to gutsy all-the-way winner Salmon Ladder in the Berkshire track's feature, the St Simon Stakes.
Bin Suroor clawed back some of the leeway when Diffident and Russian Revival gave him a one-two in the seven-furlong Racing Post Stakes, but it was the Trophy that counted.
The two Godolphin horses were running on their merits, and there was only a head between them at the line.
The favourite Russian Revival, carrying the second colours, went past Sergeyev two furlongs out and it was not until well inside the final furlong that Diffident got on terms.
Winning jockey Kevin Darley said: "Diffident has to have cover, and in such a small field I was a bit worried. But I found a nice slot behind Russian Revival and although my horse had a bit of a think once he saw daylight before he started to run, once I made his mind up for him he ran on well."
Salmon Ladder's St Simon Stakes win was no more than the four-year-old deserved after three successive second spots.
In his last three races he was beaten, by less than a length on each occasion, by Annus Mirabilis, Sacrement and Wall Street.
However, yesterday yet another close finish went his way when he held on under Richard Quinn, after making virtually all the running on tacky ground, to repel Kutta's persistent challenge by three-quarters a length.
It was an appropriate win for Salmon Ladder, who has suffered from breathing problems in the past, for his owner Martyn Arbib sponsors the Group Three contest.
Trainer Paul Cole said: "He could have been a very, very good horse but when they've had a wind operation it is like firing on five cylinders instead of six. But he's a real trier."
Tempting Prospect later gave the Queen her 600th winner with victory in the Whatcombe Stakes.Reuse content