Harbinger put up a champion's performance to win the King George VI and Queen Elizabeth Stakes at Ascot on Saturday.Trained by Sir Michael Stoute and ridden by Olivier Peslier the 4-1 second favourite, annihilated his rivals with an electrifying 11 length win over Irish Derby winner Cape Blanco.Youmzain took third.Epsom Derby winner Workforce, a stablemate of the year-older Harbinger, was the disappointing unplaced 8-11 favourite.Former French champion Peslier, who only sat on the runaway winner

Harbinger put up a champion's performance to win the King George VI and Queen Elizabeth Stakes at Ascot on Saturday.

Trained by Sir Michael Stoute and ridden by Olivier Peslier the 4-1 second favourite, annihilated his rivals with an electrifying 11 length win over Irish Derby winner Cape Blanco.

Youmzain took third.

Epsom Derby winner Workforce, a stablemate of the year-older Harbinger, was the disappointing unplaced 8-11 favourite.

Former French champion Peslier, who only sat on the runaway winner for the first time on the Newmarket gallops last weekend, said Harbinger was a champion.

"This horse today was the king," Peslier said.

"You can imagine how I felt in the last furlong (200m) when I saw the big screen and I could see the others so far behind.

"He is a champion."

It Stoute's fifth win in the King George and the 64-year-old now has his sights set on Longchamp in Paris in October and a race he has never won - the Prix de l'Arc de Triomphe.

Harbinger, who is unbeaten in four starts this year, is the new even money favourite for the autumn showdown.

The STG1 million ($A1.71 million) prize has Sir Michael well on the way to his 11th trainers' title.

Of Workforce, who posted a record time when he won last month's Derby, Sir Michael said: "Ryan (Moore) said he didn't switch off like he normally does, and the ground was plenty fast enough for him."

Sir Michael, who saddled the first three home last year, had taken the precaution of running Conduit to act as a pacemaker and he led the seven-runner field until after the turn into the straight.

Aidan O'Brien's Cape Blanco briefly challenged as Workforce began to struggle.

Peslier then unleashed Harbinger for his run up the outside and the Group One race was over as a contest, with the margin the only question remaining.

Harbinger's virtuoso performance, which evoked memories of the manner in which Stoute's ill-fated Shergar had lit up the Epsom Derby back in 1981, drew tears of joy from Harry Herbert, racing manager for Highclere Stud.

"This is such an ambition for everyone, for the stable, for Sir Michael, and for us at Highclere," Herbert said.

"We've dreamt of this all our lives, and now it's happened."