Ahead of the Newmarket Festival, Hornby had never won a Group One on home turf. That changed after Prosperous Voyage powered to victory on Friday afternoon.
Hornby doubled his success in the space of 24 hours as the daughter of No Nay Never secured a convincing victory in the July Cup Stakes.
Platinum Jubilee Stakes winner Naval Crown made the most of running towards the far side. However, it was the eventual winner who swooped past the opposition in the final furlong.
Charlie Appleby's four-year-old had no option but to raise the white flag, with Alcohol Free drawing a length and a half clear at the line.
It was a fitting victory for Alcohol Free's rider, who began his career with the Baldings and has only recently been reunited with the filly following regular pilot Oisin Murphy's suspension.
He said: "This is great, I began my career with Andrew and they've all been fantastic to me since I went there at 16.
"It was an experiment over six today. We've considered it and she's always had plenty of speed but has been so good over a mile.
"The thinking is that in this race her stamina would kick in up the hill, she'd see it out really well and that is what happened.
"This was always going to be her race over six, then the ground started to get quick but it just goes to show her guts and bravery and how tough she is and she's got form on all ground now.
"Two Group Ones in two days, who'd have thought it, it's been a crazy year but I'm in a very privileged position to ride top-class horses. So many people helped me to get here."