Decorated Knight has pounced late to record his second Group One success in Ireland for the season with a 25-1 upset in the Irish Champion Stakes at Leopardstown.

The Roger Charlton-trained five-year-old had been beaten three times since lifting the Tattersalls Gold Cup at the Curragh in May, but he bounced back in spectacular fashion in the mile-and-a-quarter (2000m) showpiece on Saturday (Sunday (AEST).

Andrea Atzeni gave him a patient ride, having him settled at the back of the field while the free-running Eminent set the pace from Success Days, with 8-11 favourite Churchill close up.

Eminent and Frankie Dettori still led approaching the final furlong (200m), but he was being attacked on all sides and finally gave way.

Wide on the track was the place to be and Decorated Knight made a decisive swoop to beat Poet's Word by a half length with Eminent another 1-3/4 lengths third.

Ryan Moore was easy on Churchill in the closing stages and ended up finishing seventh, about four lengths behind the winner.

"Andrea said he knew he was going to win turning in. I couldn't believe it," Charlton said.

"He's tough, consistent and very sound. He produced an amazing turn of foot and ran right to the line. There was nothing flukey about it.

"He's been a bit unlucky in his last couple of races. He hated the ground at York, got bashed about at Sandown in the Eclipse and ran a great race at Royal Ascot.

"I was half-thinking that this might be his last race. I guess we will now look at the Champion Stakes at Ascot."

Decorated Knight was slashed to 8-1 from 25-1 for the Champion Stakes at Ascot on October 21.