The 7lb claimer, son of former champion Kieren Fallon, struck first on Erissimus Maximus to complete a double, having earlier steered Real Estate to victory for Michael Attwater.
Fallon led from the start on Erissimus Maximus (8/1) and had enough in reserve to see off Blackheath by three-quarters of a length in the Phil Rendell Forty-Thirteenth Birthday Handicap.
"That was his first ride for me. He rode absolutely spot on to instructions - he'll go a very long way," said Murphy.
Murphy had been in two minds whether to let Erissimus Maximus take his chance, as she feared the ground might have dried out too much.
She added: "It was great. He's a horse that likes a bit of cut in the ground, so did we run or not - but it was safe good ground so we did, and taking the weight off his back gave him a helping hand as well.
"We're very pleased for him. We'd love a couple of inches of rain for this horse, but he's proven there today he can go on good, safe ground as long as there is no jar in it.
"We'll see what happens and find somewhere else for him to go again."
Fallon had earlier got Real Estate (100/30) up in the final 50 yards to deny Dalness Express in the Watch Sky Sports Racing Virgin 535 Apprentice Training Series Handicap.
It came at a cost, however as he picked up a three-day ban for careless riding.
Attwater went on to complete double on Lawn Ranger (4/1) in the Sky Sports Racing Sky 415 Handicap.
The four-year-old got on top in the final furlong to beat Mr Scaramanga by a length and a half in the hands of Kieren Fox.
PJ McDonald was another in double form, striking aboard Summer Moon (9/4 favourite) for Mark Johnston in the Watch Sky Sports Racing In HD Handicap, before adding the Follow At The Races On Twitter Handicap through the John Gallagher-trained Tomahawk Ridge (4/1).
