Williams showed he is a class act with a wonderful return. In fact he looked so sharp that I had to remind myself that he has been out for more than seven months.
He scored a try with his second touch of the ball, made the break that led to the second and then served up the Scarlets’ third on a plate.
I say this as a compliment to Scott when I say there is a touch of the Gavin Henson about him on the pitch. He is deceptively quick, is strong in defence and does the simple things exceptionally well.
Just like the best football players, Williams always seems to have time on the ball as he showed in his role in Steffan Evans’ try.
He stepped on the gas when he saw the gap, kept his composure at the crucial moment to draw the man and then deliver a scoring pass. The world-class players make the game look simple but it was deadly.
He puts himself in good positions, rarely gets caught with the ball and runs great support lines – as he did for his try yesterday.
I was relieved to see Wayne Pivac take him off after an hour. I’m sure Williams would have liked to stay out there as long as possible after so long out, but it was a sensible move. His job was done so let him come off with a clean bill of health and enjoy the occasion.
Gatland will have been especially happy to have a fit and firing Scott Williams back because it is so close to the summer tour.
His return will keep Jonathan Davies and Jamie Roberts on their toes. Williams is a very different player to that pair. He is more of a distributer and can act almost like a second receiver, again, a bit like Gav.
The sight of Sam Warburton coming off with a shoulder injury and Samson Lee taking a blow to the head will naturally be a concern for their regions and Wales. But there were far more positives than negatives from what was a great occasion at ‘Judgement Day’.
James King and Rhys Webb stood out for the Ospreys in their win over Cardiff Blues. King has made a career out of his versatility. At times against Cardiff he played in two positions, openside in defence and No.8 at attacking scrums, and he was superb.
He had a tough task given he was not just facing Sam Warburton but three natural sevens with Ellis Jenkins and Josh Navidi in there, too.
But he was strong with the ball, tough in defence and took his try really well. For such a big guy he is pretty quick on his feet to get up and over the line before the Cardiff back-row realised the ball was out of the scrum.
Players with that sort of versatility are worth their weight in gold and Gatland clearly rates King because he is always in the squad – even if he hasn’t had as much time in the jersey as he would want behind such a settled Welsh back-row trio.
But the tour to New Zealand could really be his chance to shine.
I feel sorry for the likes of Jenkins and Navidi. They are such good players throughout the season for the Blues but with two British Lions in Warburton and Justin Tipuric ahead of them for the No.7 jersey, they know it will take something exceptional to be selected.
Tipuric is out of the summer tour so this could be a chance for one of them – or James Davies who played well for the Scarlets – to squeeze their way in.
I loved watching the duel between Dan Biggar and Gareth Anscombe, two completely different No.10s but both effective.
Anscombe had one of his best games for the Blues. He takes the ball flat, runs hard and creates problems.
His vision and pass for Aled Summerhill’s try was fantastic. He took the gamble and it paid off. Biggar sits deeper, creates space with a pass or kick and gets team-mates playing off him.
One dark horse for the tour could be Adam Hughes. There are places up for grabs in the back three and he was a surprise package at the Principality Stadium.
His work-rate was phenomenal and he finished his try well. He probably out-shone Hallam Amos, who I rate highly.
Another major plus was a wonderful crowd of more than 68,000, proof that if the regions and WRU work together and the ticket pricing is right, then there is still a huge appetite for regional rugby in Wales.
There is often so much negativity about our professional game that it was great just to see a spark of excitement about the place for two derbies.
Away from the rugby field I am glad to report that I ran a personal best of 3 hours 32 minutes at the London Marathon last week.
But, more importantly, I was able to raise plenty of money for Velidre Cancer Centre so thank you to everyone who helped with my sponsorship.