Charlie Appleby's remorseless galloper led after the first furlong and was never headed as he added his second successive Group One following last month's success in the Coronation Cup at Newmarket.
Enable, having her first run of the campaign and absent since finishing a gallant second in last year's Prix de l'Arc de Triomphe, was held up off the pace by Frankie Dettori and could never get to the winner - eventually finishing a 2-1/4 length runner-up.
"Charlie had him in great shape. We were obviously concerned about Enable coming into the race, but it was her first run of the season and I'm sure she'll improve from the race," Buick said
"As a horse, you go with what Ghaiyyath wants to do - he's not a horse who likes to be controlled. You just sit against him, let him use his huge stride and go when he's ready.
"He's a joy to ride and a very, very good horse. As a five-year-old he's mature physically and mentally - he's becoming the finished article.
Despite the defeat, Gosden was understandably thrilled with the effort of Enable.
"I'm delighted with her. She ran a gorgeous race. We know Ghaiyyath and as I warned everybody it is a great front-runners track, Sandown," Gosden said.
"She enjoyed it and her zest and desire is there, but trying to get involved with a front-running horse like him was never going to be her deal.
"I think I did warn everybody about that left, right and centre."