Tower Of London showed a good engine to land the Listed King George V Cup despite drifting markedly right in the closing stages.

He brought up a double for Aidan O'Brien and Ryan Moore after the earlier success of Buttons in the juvenile fillies' maiden.

The 11/10 favourite came to grab New Variant racing past the two pole and was ridden to wind up the pace at the furlong marker.

He kept on best but in the final 100 yards veered across to the centre of the track. Moore kept him going to pass the post with a length and three-quarters in hand. Market-drifter Shamwari (16/1) chased him home .

"We're delighted he won but we didn't learn a lot as it was a very slow pace,” said O'Brien.

“We know that he can quicken, he did that as a two-year-old. There are a couple of races in Ascot, he could go either a mile-and-a-quarter or a mile-and-a-half.

“He might be a horse that likes to take his time and not be produced until late, Ryan gave him a perfect ride because they were going so slow he had to go.

“He ran bad in the Derby trial and that was probably the ground and he was a bit keen behind Auguste Rodin here last year.

“Looking at him he's probably a mile-and-a-quarter plus horse who wants plenty of pace on in front of him and to take your time. I'd say that's him.”

When asked if he could be a Leger horse like his brother Capri he added: “Maybe, but I don't know whether he'll stay that far. He tanks a bit, he's a strong traveller.

“He'll come forward from the run as he still had a bit of a tummy on him. We'll play it by ear, but Ascot is the plan and we'll see then if he comes out of that okay.”

Paddy Power halved Tower Of London from 40/1 to 20/1 for the King Edward VII Stakes and from 50/1 to 25/1 for the St Leger.

Additional reporting by Gary Carson