Lancaster Bomber got a deserved big race win to his name, as he made all in the Group 1 Tattersalls Gold Cup.

Successful in a maiden at Leopardstown in 2016, the son of War Front was placed six times at the highest level since, and was third in the Lockinge Stakes at Newbury just last weekend.

Available at 10/1 in a place in early shows, the bay colt opened on-course at just 9/2 before going off a well-supported 10/3 chance under Seamie Heffernan.

Having raced in a clear lead, his advantage was reduced from the two furlong pole.

He appeared a sitting duck from a furlong out, as the market leaders closed-in, however he responded well to pressure inside the final furlong, pulling out more to score by two lengths.

The easy to back Cliffs Of Moher (4/5 in early shows, returned 7/4) was second under Ryan Moore, while the 5/4 favourite Defoe was another length and a half back in third.

"He's been running at the top level the whole time, all in Group 1's, and obviously we didn't think he'd get a mile-and-a-quarter," said O'Brien.

"That's the first time we did it with him and let him roll on beautiful ground. He was there for everyone to follow and Seamus gave him a great ride, he went even to halfway and he kept going.

"He was happy to get a lead but he was going to go level and we were happy to make the running also. He got left there so he Seamus did the right thing.

"The plan was to come here and then go back to Ascot for the mile race again. I'd imagine that's where he'd go but he'd have an option of the Prince Of Wales now.

"We thought that the Curragh is a tough place to get a mile-and-a-quarter but he didn't flinch and he kept going.

"It was a great run from Cliffs Of Moher and we were delighted with him. He relaxed well and came there but just couldn't get past the other horse. We were very happy with his run, it was a very solid run.

"They found themselves and little bit back off of him (Lancaster Bomber) but he just kept going in front and didn't surrender.

"His form is very solid and his last run in the Lockinge was a very good run.

"We were thinking of coming here and going to the Prince Of Wales with Cliffs Of Moher so we'll see now and obviously Idaho goes next week to the Coronation.

"Some of those horses are still progressing and I'd say he progressed again. He's rated 116. It's a high rating and he's still not finished with maybe."

Additional reporting by Gary Carson