Cleary rode a copybook race, tracking the trail-blazing Former Senator into the straight and then launching his challenge.
It looked as if Former Senator had stolen the contest off the final bend, but the youngster timed his effort to perfection and High Priestess quickened past in the last hundred yards.
The daughter of Priolo was giving trainer, Michael O’Brien, his third winner of the week and he was once again represented by assistant, Denis Cullen.
“I rode her here myself on Monday night in the GPT to finish fourth”, said Cullen. “She gave me a great spin, but was just a bit rusty, not having run since Christmas. Rory is a great, great rider and will make Galway his own!”
The Smirnoff Black Ice Maiden was a huge betting race, with the vast majority of the money falling onto John Oxx’s Akilana and Dermot Weld’s Muntami.
But the layers got a screamer, as Aidan O’Brien Starrystarrynight scored in the proverbial canter.
The daughter of Sadler’s Wells made no show on her debut at Gowran Park - 31 lengths last of 11 behind Misty Heights.
But she stripped a different machine here, powering past the front running Akilana two furlongs down and easing clear in the straight to score by three lengths.
“She was a little bit green at Gowran and came on for that run”, reported travelling head-man, Pat Keating.
“I’m getting the hang of training these jumpers”, quipped Dermot Weld, after his Stage Affair had stayed on in fine style to grab the Tony O’Malley Memorial Handicap Chase.
It was a decent effort on the part of the veteran, considering he was badly hampered at the first when Wouldn’t You Agree and Alan Crowe parted company.
David Casey gradually worked his charge into the contest, but Stage Affair was still only sixth turning for home.
He found a real surge in the closing stages, however, flying past the flattering Green Finger to win going away by a length and a half.
“That was a lovely ride from David”, said Weld, well pleased a horse who scored for him on this track eight years earlier as a two-year-old had again done the business. It was Weld’s sixth winner of the week.
Galway Hurdle hero John Cullen, who took a fall from City Hall, was stood down until Monday with a bruised shoulder.
Swiss Roll, beaten less than two lengths by Sandy Owen at Killarney, reversed placings in the Harp Lager Race.
Sandy Owen, taken at 5-2 in the morning and from 7-4 to 11-8 on track, looked the likely winner when driven ahead by Jamie Spencer off the home turn.
But the talented Billy Lee conjured a terrific late burst from Tommy Stack’s filly to touch off Sandy Owen close home.
Stack was represented by his son, Fozzy, who said: “She was better in today and stripped fitter than Killarney.
“You need luck round here and, thank God, fortune was on our side.”
A gamble on the Niall Madden trained Team Allstar in the Carlsberg Lager Handciap Hurdle proved well wide of the mark.
Early offers of 5-2 looked tight, but punters thought he was value, backing him into 7-4. The favourite was never very convincing through the contest, jumping sloppily at times, and was beaten coming away from three out.
Victory went to the Peter Casey partnered 20-1 shot Pease Blossom, who got the best of a tough battle with Lord Of The Grove from the final flight.
Mr Jaykay streaked away with the Smirnoff Ice Handicap, after Tadgh O’Shea had produced him to lead at the furlong pole, the verdict five lengths.
The attendance was the biggest for a Friday night in the history of the Festival, 28,654.