The Portugal captain was nearing the conclusion of his first season at Old Trafford at the time and had shown glimpses of his world class potential.
Now, at the age of 36, Ronaldo is in his second spell with the Red Devils and has established himself as one of the very best in the world, and in the history of the game.
The former Real Madrid and Juventus forward had to bail his side out twice in the Champions League on Tuesday night against Atalanta, scoring right at the death to secure a 2-2 draw.
Yet Murphy remembers a time when the ruthless finisher was a mercurial winger, capable of being marked out of games and even losing his head.
The former Liverpool midfielder had a penchant for securing 1-0 victories for the Reds at Old Trafford, normally via a set-piece, just like he did in April 2004.
A rash Gary Neville challenge in the box on Steven Gerrard afforded Murphy the chance to score from 12 yards and he remembers how an 18-year-old lost his head at 'The Theatre of Dreams.'
Murphy even then offered a hand to the Portuguese, only to be 'told where to go' by the moody star.
"You always knew he had a talent," Murphy said on White and Jordan. "I never thought he would go on to do what he did.
"But he was special, he was special. It was like, 'Oh my God he's got the ball, we have got to double up on him and stop him.'
"But I never forget that game you're talking about funnily enough, because he tried to two-foot me - he lost his head and we were beating them.
"He missed me thankfully, so I didn't go over and, because I was cool and calm because we were winning, I put my hand out as if to say 'don't worry about it.'
"I gave him a little high-five or a slap - or whatever you want to call it - and he told me where to go.
"So I was fuming with him and I just thought. 'I've just saved you a red card!'"