Teenage jockey Oisin Murphy clocked up four victories in one afternoon at combined odds of 9,260-1, with Highland Colori's Ayr Gold Cup win the highlight of his winning run in Scotland.
The 20-1 shot finished more than a length ahead of Louis The Pious (25-1).
"I'm a bit shocked," Murphy said. "I thought the horse might be a bit out of his depth."
Top weight Jack Dexter, Scotland's best hope of a first home winner of the six-furlong sprint since 1975, came third.
However, there was some joy for the hosts, with the winner owned by Scot Evan Sutherland.
Highland Colori, who was touched off a short head by Mass Rally in last year's Silver Cup, emerged from the bunch at just the right time to ease home.
Earlier this week trainer Andrew Balding stated that Murphy would not be riding in races worth less than £6,000 in an attempt to keep hold of his claim for as long as possible, and it is easy to see why.
Carrying a penalty for a win over seven furlongs at Warwick last month, the winner broke from stall 19 as the field converged on the near side rail.
For a brief moment Jack Dexter threatened to deliver a long-overdue home win, but Highland Colori could not be caught.
Murphy went on to make it a double as he guided the John Quinn-trained Levitate home, and then a treble as he made the most of a spare ride on the Linda Perratt-trained Silver Rime.
Locally-based Perratt said: "I was delighted to be able to get Oisin when Phillip [Makin] was unable to ride. He said he had never been to Scotland before but I bet he will want to come back now!"
Murphy rounded off a stunning afternoon with victory on Cockney Sparrow in the Jordan Electrics Ltd Handicap, and said: "I can't believe it, the day's got even better."