Wilshire Boulevard outpointed better-fancied stablemate Oklahoma City to give Aidan O'Brien a one-two in the Jebel Ali Racecourse & Stables Anglesey Stakes at the Curragh.
Oklahoma City was sent off the evens favourite having won a Naas maiden by 13 lengths last time, and Joseph O'Brien soon had him in the lead on the stands rail.
He ran on strongly, but was no match for Wilshire Boulevard (7-1), who seemed to relish the step back up to six furlongs as he challenged a furlong and a half out under Seamie Heffernan and scored by three-quarters of a length.
O'Brien said: "We left the hood off today and he settled well. He's a brother to Zoffany and like a lot of the Holy Roman Emperors (sire), he seems to be improving."
The Ballydoyle handler added of the runner-up: "I was happy with the run and he will probably step up to seven furlongs now."
The day's riding honours went to Johnny Murtagh, whose Oaks victory on Chicquita was the middle leg of a treble.
He avoided the hard-luck stories on the inside as he swooped at the furlong pole on Eddie Lynam's top-weight Pearl Of Africa (9-2) to take the Sycamore Lodge Equine Hospital EBF Fillies Handicap in impressive style by two and three-quarter lengths.
The trainer said: "She is out of a good Group One winner (Kournikova). Sheikh Fahad kindly sent me a yearling and this is it. She goes on any ground, although she looks around her a bit and that's probably helped her to win three on the bounce.
"She'll go for some black type now. There are plenty of options in Listed and Group Three company. I'd like to leave three weeks between races with her."
Murtagh later rallied Belle De Crecy (2-1 favourite) to take the Kilsaran International Handicap for his own yard, and said: "She was hanging a bit left as she was feeling the ground and I probably won't run her on ground that fast again, but she stayed at it well and an extra furlong would be ideal for her. We will give her a little break now."