The first hour of last Saturday’s international between Wales and Ireland was something incredibly forgettable, especially if you were supporting the home team.
It was slow going, one dimensional and error strewn attacking play that hardly resulted in a try scoring opportunity and giving Ireland the set piece platform required to take a commanding 22-3 lead.
However, the final quarter of the game was almost a total change, as Wales dominated possession and territory, scoring two tries and looking the team which won the Grand Slam and had a 14-game winning streak, even with a much changed side.
The difference? Well there was a few. Some weight and dynamism in the pack, avoiding the scrum and Rhys Patchell adding some impetus at fly-half.
In my eyes though, the main difference was Tomos Williams and what he offered at scrum-half, having come on for the hesitant and dithering Aled Davies.
The reason Tomos Williams can come off the bench and have such an impact from scrum-half is because he knows he can manipulate the defence from the base of a ruck or a scrum, and sees the space that this can open up.
He mixes up his game well, not afraid to show-and-go on the inside if he spots a gap, but not someone who snipes for the sake of it. In the first clip he spots that Rory Best is covering a large guard area by himself so uses Rob Evans as a dummy runner and but for Tadhg Beirne covering has a chance to push towards the try line.
That is where manipulating the defence starts, as when Williams moves off the back of a scrum the inside defender has to hold on the scrum-half, leaving Owen Watkin the chance to carry at a defender one-on-one.
That manipulation then allows Tomos Williams to dictate the pace of the game from scrum-half, picking and choosing when the time is right to inject speed of ball.
His delay of the ball in the first clip briefly slows the game down but also catches Jordi Murphy out at guard who goes to step forward but has to hold himself, as well as holds the attention of Tadhg Furlong at bodyguard.
Watkin can then run straight at Devin Toner, making a yard after contact before Williams gets quick ball to once again target Murphy who has a couple of yards to cover, going to the outside and allowing the scrum-half to step inside him.
Similarly here, Tomos puts a foot on the brake briefly, taking a phase of one-out carrying to allow quick ball and then holding the attention of Jack Carty long enough to allow Scott Williams to run at a weakened shoulder and get over the gain line.
In his 33 minutes on the field Williams made 33 passes, just 14 less than Aled Davies who had 57 minutes on the field despite the fact that for the majority of his first 15 minutes of game time Wales were camped in front of our own try line going from defensive scrum to defensive scrum.
His ability to control the game with ball-in-hand is impressive, but for a young man his communication and reading of the game is equally important, in each example above he can be seen barking orders at forwards, whom he organised twice into pick-and drive sets, causing the Irish defence to narrow.
The awareness of when to go wide leads to two tries, working well with Rhys Patchell for the second try, a partnership which will now continue this weekend.
If they both spark an attacking performance like that we saw in the final 20 minutes at the Principality Stadium last week then calls for them to start the first game in Japan will no doubt increase.
For Tomos Williams by himself though, now fit and firing he is putting serious pressure on Gareth Davies for that number nine jersey, and it wouldn’t be a bad bet if you put money on him getting the majority of World Cup minutes at scrum-half.