Ridden by Shane Foley, who won the Irish 1,000 on Jet Setting in 2016, Romanised ran out an authoritative winner as he came from way off the pace.
Mark Johnston’s British raider Elarqam - fourth in the 2000 Guineas at Newmarket - broke smartly and shared the pace with Aidan O’Brien’s US Navy Flag.
The race looked wide open with several in with chances, including Charlie Appleby’s Symbolization, Gutstav Klimt and Threeandfourpence, but Romanised was produced with a sweeping run in the centre of the course to land the Group One spoils.
US Navy Flag and Gustav Klimt were second and third for the O’Brien team.
Middleham trainer Johnston saw his favourite come home a well-beaten sixth.
Condon - winning his first race this season - said: “We kept faith in him and he had excuses at Naas on his comeback.
“He worked the best he’s worked all spring last Tuesday. We knew we were a long shot coming in here, but I felt he was going to run a big race.
“He’s always shown talent and he just seems to have come to himself in the last few weeks.
“I’m in a bit of shock and it will be a few days before it sinks in. It’s just amazing to win a classic. It’s all I wanted to do when I entered racing.
“It’s a very select club and to actually step into that club feels like you are walking through special doors to be considered one of those.”