I should have listened to George Duffield. Sandown Park’s Eclipse Stakes, the first time the Classic generation of three-year-olds take on their elders, is one of my favourite races and the then 53-year-old rider’s triumph on Giant’s Causeway in 2000, beating Kalanisi by a head after Pat Eddery had driven him into the lead 200 yards from the finish, was the duel I will never forget. Duffield was Sir Mark Prescott’s stable jockey and soon after that race the Newmarket maestro took a call from Aidan O’Brien, Giant’s Causeway’s trainer. ‘Whatever you do Sir Mark,’ said the quiet Irish voice, ‘make sure you breed from him before you let him go!’

This year’s Eclipse was a fascinating prospect. Vying for favourites were O’Brien’s three-year-old Paddington, winner of the Irish 2000 Guineas and victor at Royal Ascot in the St James’s Palace Stakes, and Emily Upjohn, the four-year-old filly who won the Fillies and Mares Champion Stakes last year and took this year’s Coronation Cup at Epsom.

William Haggas’s five-year-old Dubai Honour, twice a Group One winner in Australia, was no remote prospect and the Crisfords’ West Wind Blows, a Group race winner in France, completed the field. What made the contest especially intriguing was that Paddington’s Group 1 victories were over a mile, while Emily Upjohn’s were gained over a mile and a half. For the ten- furlong Eclipse, she was dropping down in trip, while Paddington was moving up.

From the start my heart was with Emily Upjohn, who last summer, at a time when she was one of this column’s Twelve to Follow, had been desperately unlucky to finish second in the Oaks after losing many lengths with a stumble at the start.

Statistics offered some cheer: horses like Paddington stepping up in trip for the race had only once succeeded, while horses dropping back in trip like Emily Upjohn had a strike rate of 19 per cent (seven winners from 36 qualifiers).

But I was not happy to see George Duffield comparing Paddington to Giant’s Causeway, who went on after his Eclipse victory to win the Sussex Stakes, the Juddmonte International and the Irish Champion Stakes, his haul of five Group One victories in 13 weeks earning him the nickname of ‘The Iron Horse’.

Describing Paddington in the Irish Guineas as ‘a big sloppy bugger’, George declared pre-Eclipse: ‘All of a sudden the penny dropped. He went “voom” and it was all over. He proved at Ascot he’d come on leaps and bounds from that race and I think he’ll improve again. He looks to me like the sort of horse who’ll get a mile and a quarter stood on his head he’s so laid back. He does what’s required but with a lot of quality and class.’

When I came close to Paddington in the paddock at Sandown, I knew in the pit of my stomach that George Duffield was right. One reason I am a scribe and not a racehorse trainer is that I can only marvel at trainers’ sixth sense, the way they tell a horse’s wellbeing and judge the work he needs by the bloom on his coat, the twitch of his ears, the jauntiness of his stride. But gazing at Paddington’s massive chest with all the space it provides for heart and lungs I commented to my neighbour: ‘I can’t believe it but I think he’s actually grown in the 18 days since Ascot.’

Emily Upjohn, too, is a fine big filly, one with the precious ability to quicken, but Lester Piggott once told her co–trainer John Gosden that the race conditions of the Eclipse definitely favour the three-year- olds. A three-year-old filly carries 8st 10lb and a three-year-old colt or gelding 8st 13lb. For four years old and upwards, fillies carry 9st 6lb, the colts and geldings 9st 9lb. So although Emily Upjohn was receiving three pounds from Dubai Honour, she was having to give Paddington a seven pound weight-for-age allowance.

The race was an enthralling duel with Paddington and Emily Upjohn pulling six lengths clear of the other two. As jockey William Buick and Emily Upjohn came to tackle Paddington, the crowd roared her on, but although she remained within half a length of the winner at the post it never quite looked as though she was going to be able to get past him, even if his head carriage was a little high. She lost nothing in defeat however and remains on target for the Arc at the end of the season.

As for the winner, it seemed my eyes had not deceived me in the paddock. Paddington’s trainer, Aidan O’Brien, celebrating his sixth success in the race since Giant’s Causeway’s victory, declared that Paddington was surprising him, doing things no other horse had done: ‘He’s put on a bit of weight since Ascot and it’s strange for a horse to do that. He’s been progressing with every run, getting heavier, stronger and quicker.’ Paddington, he said, was ‘a lot quicker’ than Giant’s Causeway. ‘There’s something very different happening.’ Ominous.