The 30-year-old had to bide his time during the early stages of his international career, as Dwayne Peel kept a firm hold on the starting scrum-half role.
But Warren Gatland's arrival as head coach tipped the scale in Phillips' favour, and the 6ft 3in half-back has made the number nine shirt his own since.
The 2009 Lions Test scrum-half is in line to win his 77th Wales cap in Saturday's titanic tussle with Grand Slam chasing England, overtaking the mark of 76 he currently shares with Sale number nine Peel.
Williams has acted as understudy to Phillips throughout this Six Nations campaign, and has heaped praise on his colleague.
He said: "It is a huge credit to him to become the most-capped scrum-half that Wales has ever had.
"He is such an important player, such an experienced player and he brings a real physical edge to the game.
"You can tell that all the boys in the squad have a lot of respect for him.
"He is a very good player. He likes to put tempo on the game, he is an attacking threat and he is very good defensively.
"He is one of the best scrum-halves in the world defensively, he is a very strong presence on the field and it is a great achievement for him. He fully deserves it."
Williams has yet to play against England, having been an unused replacement when Wales clinched the Triple Crown at Twickenham last season.
But his father Brynmor was part of the Welsh side that beat England 21-19 at Cardiff Arms Park in 1981.
The elder Williams was key in securing Wales' win that day as his dummy was enough to draw Clive Woodward offside and set up Steve Fenwick's decisive penalty.
And Cardiff Blues' half-back Lloyd has a keen sense of just how intense the rivalry between the two nations is.
"I'm pretty sure my dad sat me down to watch a video of it when I was a kid," said Williams.
"From a young age you are always aware of the rivalry with the English.
"It will be more evident than ever this Saturday as the championship is riding on it and it is a massive occasion.
"But a lot of the boys in the squad have experience of these big games over the last five years. That is really going to help us out in difficult situations.
"We won against them last year, but I did not get on the field so it would be great to feature in a win this time."