The Londoner guided the Magpies to fifth place in the 2011/12 season and took the team into Europe, but a key victory over Manchester United at St James' Park helped them on their way.
Pardew, speaking to the Coach's Voice, said: "You suddenly beat Man United 3-0 and I am shaking hands with Fergie on the sideline.
"I'm thinking: 'He's not going to be too happy.
"I did find out he wasn't too happy because he never spoke to me for about 14 months.
"Prior to that, he'd been texting me to say how well I'd done and everything. When you come up against these top managers you have to understand that everything is fine.
"They can be very nice gentlemen until you beat them.
"Fergie is still a dear friend of mine but he did have a little bit of a sulk over that result."