Star lives up to the hype by outshining his rivals

O'Brien's sights on July Cup after Choisir's son handles straight six in overdrive

Back in the spring, before Starspangledbanner had set foot on a racecourse outside his native Australia, his adopted Irish trainer Aidan O'Brien warned that, such was the speed the horse had displayed before him on the Ballydoyle gallops, a safety harness and parachute would be de rigueur for his jockey. After only a fifth place on his northern- hemisphere debut at York, such an opinion, even if given tongue in cheek, smacked slightly of hubris.

But here yesterday, on the biggest stage when it mattered, Starspangledbanner showed his true measure, hurtling down the straight six furlongs to take the Golden Jubilee Stakes, its £255,000 prize and its Group One kudos like an equine Usain Bolt. "I could hardly pull him up after the race," said Johnny Murtagh, in the saddle. "He's in a different zone to any sprinter I've ridden."

Starspangledbanner, twice a top-level winner at Caulfield for Leon Corstens back home, joined O'Brien with the aim of enhancing his global stallion potential. And although speed has always been prized in Co Tipperary – legend has it that the mythical Finn McCool took as bride the woman who ran swiftest to the top of the local peak, Slievenamon – there has not, apparently, been a horse like this one.

"The first time we worked him properly, we had to check the GPS timing system," said O'Brien. "He'd clocked 9.5 seconds through a furlong and I've never seen one do those fractions before. He's incredible; he works like a quarter horse."

The 13-2 joint favourite to emulate his sire Choisir's victory seven years ago, Starspangledbanner was never headed and hardly challenged as he shot rocket-like from his starting stall. The 50-1 shot Society Rock, nearly two lengths adrift at the line, did best of his 23 rivals, followed in by Kinsale King (8-1) and the other joint favourite, Fleeting Spirit.

"He's quite extraordinary," added O'Brien. "He walks around almost in slow motion, yet his reflexes are so fast. I knew if he hit the gate nothing was going to lead him. And he's won over a mile in Australia so he wasn't going to be stopping at the end."

When the Australian-trained Choisir added the Golden Jubilee Stakes to the week's five-furlong feature, the King's Stand Stakes, he opened the door to international competition and yesterday's contest was a microcosm of the global nature of the thoroughbred industry. The winner is Australian-bred, Irish-based; the runner-up and fourth Irish-bred, British-based; the third bred and trained in the US. They were followed in by two trained in France, the German-bred Amico Fritz and Australian-bred War Artist.

Starspangledbanner's next target will be the July Cup, which O'Brien has taken with two sprint champions, Stravinsky and Mozart, and for which he was backed to 7-2 favourite yesterday. "He came forward hugely from his York race," said O'Brien, "and he won't make the same progress again. But if we can hold him where he is, I'll be looking forward to watching him again."

The chestnut's rivals will include his compatriots Denman and Nicconi, last year's winner Fleeting Spirit and her progressive Jeremy Noseda-trained Laddies Poker Two. The last-named grey mare, another by Choisir, covered the six furlongs three-tenths of a second faster than Starspangledbanner as she ran away with the Wokingham Handicap after a 610-day absence, but she was carrying 7lb less.

Laddies Poker Two, who carries the Coolmore colours normally associated with O'Brien inmates, landed one of the gambles of the meeting, 25-1 last week and backed from 10-1 in the morning to 9-2 favourite. "The plan to win this was hatched in December 2008, but had to be put back a year when she picked up an injury last spring," O'Brien said.

Sir Michael Stoute may have a dilemma next month. It was announced yesterday that his charge Workforce, winner of the Derby, will miss next weekend's Irish version of the Classic in favour of a tilt at the older generations in the £1 million King George VI and Queen Elizabeth Stakes.

The Khaled Abdullah colourbearer is hot favourite for the all-aged showpiece; second market choice is now his stablemate Harbinger, who continued his progress up the ranks towards the top flight in the Group Two Hardwicke Stakes. The four-year-old forged smoothly clear of the trailblazing Barshiba in the straight under Ryan Moore and was vainly chased home by Duncan.

The two Stoute horses are in different ownership; Harbinger carries the silks of Highclere Racing. "We'd love to come back for the King George and take on Workforce," said the syndicate's manager, Harry Herbert. "Harbinger has been a different horse since he had a minor operation to help his breathing over the winter. He's very special and a Group One race is now the challenge."

Three-times champion Moore was his usual low-key self about the Dansili colt. "He did it well and enjoyed it," he said. "He quickened well but he's beaten inferior horses."

Moore took the week's riding title by winning the closing Queen Alexandra Stakes on Bergo, equalling Murtagh's score of four but bettering his placings countback.