The 29-year-old found himself relegated to fourth-choice central defender in the wake of the Magpies' January shopping spree, which added Montpellier's Mapou Yanga-Mbiwa to a pool already containing skipper Fabricio Coloccini and home-grown talent Steven Taylor.
However, injuries to Coloccini and Taylor in recent weeks have resulted in a recall for a largely unsung hero, and with both men fighting a race against time for Sunday's short trip to Sunderland and Yanga-Mbiwa suspended, he could yet find himself the mainstay once again.
Williamson has started the club's last two games, a 2-1 Barclays Premier League win at Cardiff and last Saturday's 2-2 draw with Liverpool in which he led a concerted rearguard action following Yanga-Mbiwa's first-half dismissal, and Pardew is confident he will get more of the same from the player this weekend if required.
He said: "There have been times I have looked past him for other players, but he has always handled that well and whenever I have put him in, he has never let me down.
"His stature, particularly at set-plays, gives us a slight advantage where we have a slight disadvantage without him.
"I think he has grown as a player - centre-halves do, they get better with age, so I think he has got better since I have been here and that has been reflected in some of his performances."
Williamson, who arrived from Portsmouth for an undisclosed fee in January 2010, has had to remain patient after slipping down the pecking order at St James' Park.
However, Pardew has been delighted with his attitude and his determination to force his way back into the team.
He said: "He is actually very intelligent and laid-back. Sometimes that can mask a little bit - I have had centre-halves who are tearing about and want to take on the world who are not as brave as Willo.
"He knows the Premier League, he has been doing it now for three years at this football club under my supervision and as I say, I think he has improved as we have gone along."
The battling draw with Liverpool will send the Magpies to Wearside brimming with confidence and determined to gain revenge for last season's shock 3-0 home defeat by the Black Cats.
Sunderland manager Gus Poyet will take charge of the team in a home game for the first time desperate to bounce back from a 4-0 defeat at Swansea in his opening fixture, and Pardew knows it will be a difficult 90 minutes despite the Black Cats' dreadful start to the season.
He said: "This is a very different game. It's Gus' first home game as the manager of Sunderland, so there will be an extra-special atmosphere there and we need to be prepared for that.
"Hopefully we will be. We have got a good side, we are a very attacking side and we are good to watch when we are in full flow, and hopefully we can bring that to the surface on Sunday."