Power made amends for an abject seasonal reappearance with an electric performance in the Abu Dhabi Irish 2,000 Guineas at the Curragh.
The Aidan O'Brien-trained colt trailed home 17th of the 18 runners in the English Guineas at Newmarket when he may not have been fit enough to do himself justice, but that race and a return to quicker ground saw him back to his best.
However, the easy-to-back 5-1 shot looked an unlikely winner even a furlong out, but a strong ride from Joseph O'Brien saw him gain the day.
Power's stablemate Daddy Long Legs, who was pulled up in the Kentucky Derby, set the early pace under Colm O'Donoghue, with fellow O'Brien inmate Wrote the only one to follow his lead.
The pair built up a healthy advantage over the rest of the field and were still well in control two furlongs out.
But the distress signals were out thereafter with O'Donoghue pushing his mount along while Seamie Heffernan aboard Wrote was also getting to work.
With just a furlong left to run, the field still had plenty of ground to make up, but first the Bryan Smart-trained Foxtrot Romeo and then Power emerged to challenge.
Power's change of gear was thoroughly impressive and when O'Brien jnr finally got his head in front, the Oasis Dream colt pulled a length clear in style.
Foxtrot Romeo, a 33-1 chance, outran his odds to claim the runner-up prize with Reply filling the frame at 25-1.
O'Brien, who was equalling the legendary Vincent O'Brien's record of 27 Irish Classic wins, said: "I'm delighted, what can I say. I'm privileged and delighted.
"We were very happy with Power last year. At Newmarket it was his first run of the year on very soft ground and Ryan (Moore) rang during the week and just said 'he felt like a serious horse during the first half of the race but then he lost in the second half of the race' and we put that down to maybe needing the run and the soft ground.
"Ryan was anxious that Joseph would ride him (from the other Ballydoyle runners) and how right he was. I'm delighted it worked out so well.
"He has a lot of class and they can't go too fast in a race for him.
"I have to credit all the team at home including Keith Dalton who rides him out every day - it's a big team effort.
"He's a big, powerful horse, hence his name, and I'd say he'll go for the St James's Palace now."
The winning rider said: "They went a very good gallop and my horse was nice and relaxed.
"I was creeping away down the rail and I had plenty of cover. I didn't want to get to the front too soon and the lads were a long way in front.
"I wasn't sure if I was going to get to them but in fairness, he quickened up very well when I needed him.
"I have to thank Ryan Moore, he rode the horse at Newmarket and, in fairness, he said he felt like a good horse for the first part of the race and he just didn't come down the hill on the ground.
"He said that he thought this fella was the one so a big thanks to him.
"He's a classy horse and he has plenty of speed."
The O'Brien team also indicated Daddy Long Legs could now go for the Secretariat Stakes at Arlington in America after hanging on for fourth.
Sea The Stars' half-brother Born To Sea ran on to make good late headway behind the principals and eventually took fifth for trainer John Oxx.
Jockey Pat Smullen said: "I was very pleased with him. The number one objective was to get him to settle but once he did, I was too far behind.
"Hopefully he will progress and I think he has the ability to be a nice horse once he starts doing things right."
Richard Hannon's Trumpet Major was sent off the 9-4 favourite but finished last of the 10 runners and was later reported to be coughing.