Townsend's charges can reproduce form in Dublin
What a performance from Scotland. You have to applaud each and every one of them. I have already heard a few people say how badly England played and how Eddie Jones is going to be reading them the riot act.
But, honestly, what a performance from Scotland. We saw in the November internationals how dangerous this Scotland team could be, when they beat Australia and pushed the All Blacks so close. The instigator of that fast, attacking rugby was Vern Cotter - I think he deserves a lot of credit - and Gregor Townsend has come in and added to it.
The lessons learned were very much on Scotland's side and the big one for them from yesterday is they now have an attacking blueprint to go forward with.
If you talk about teams learning quickly, they are a fantastic example. They had the intensity, the accuracy and the heart to play that way against the second best team in the world. Their breakdown work was exemplary. Eddie Jones is always saying how he wants his England team to be the fittest in the world. But I thought Scotland looked fitter.
It helps, of course, when you are playing in front of a packed Murrayfield who can smell English blood in the water. The atmosphere in Edinburgh was absolutely electric - it took me right back to 1990 and 2000. But Scotland had to earn the right to get the crowd going like that.
I think Scotland played probably the best first half of rugby I've seen in a decade. Tactically, technically, they were dominant in all areas. What I liked most about them was they were calm, they did not panic, they were composed. Right from the start Scotland were playing quick, short passes.
They were just a level higher, a level quicker. And, at the heart of that was Finn Russell. After his horror show at Twickenham last year - and his first couple of games in this year's tournament - there was a lot of pressure on his shoulders.
Well, I always say rugby doesn't make characters, it finds them. And I think we certainly found one yesterday. Eddie Jones was right when he predicted Finn Russell would be Scotland's danger man. That was a champion's performance and showed the true measure of the man.
Tactically, he was on the button. His passing was crisp, he moved his forwards in the right areas, and he got his backs on to the ball. I was particularly impressed by Huw Jones who consistently took the ball at speed and ran nice lines.
Grant Gilchrist, Stuart McInally, John Barclay, Hamish Watson . . . I'm pulling names out of a hat here because they were all magnificent. The front row is never going to be a force, but as long as they can hold their own they don't need to be. If they can give Scotland parity, that is enough to be able to implement the game plan Gregor wants them to play.
England, by contrast, looked ponderous. Owen Farrell and George Ford were largely anonymous. I think they probably felt they would have enough to win and that Scotland would make mistakes. But they just never really got going. Jones will hate that most of all.
After Farrell scored his try so quickly in the second half, you knew it was going to be a different type of game but again Scotland reacted so well. That they went another 38 minutes without conceding a point is hugely to their credit.
England, to be fair, reacted well to Sam Underhill's yellow card (which I absolutely agreed with, by the way) and really put some phases together in the last 15 minutes. However, Scotland adapted so well and ended up with two turnovers under the posts. It was unbelievable stuff.
The question now is whether they can manage to produce that kind of performance away. You want your home ground to be your fortress and Murrayfield is becoming that for Scotland. Australia, New Zealand, France and now England have all found that. Can they do it in Dublin?
As I say, they now have an attacking blueprint to do so. Gregor will be most pleased with a combination of all the little things - all the details. Yes, it was built on the breakdown and the work in the contact area, and on Russell's brilliance, but it was the way they adapted, stayed focused, reorganised in the second half and stayed so accurate. They conceded so few penalties. Gregor can show his players this game and say 'there you go. Reproduce that'. But in the end you have to have the confidence to be able to go away from home and do it.
The game at Murrayfield was preceded by an absolutely extraordinary game in Dublin. Wales did what they did at Twickenham, conceding most of the territory and possession and paying the price for it. If Wales had played for the first 65 minutes like they did in the last 15 minutes, they might have won because when they did get the ball out wide they proved they were a threat. I wasn't impressed by their breakdown work, I have to say.
Ireland are now in position A to win the championship. But just because they are the only team left unbeaten does not mean they are likely to win the Grand Slam. You can't just say that because so and so has won one game that they are any more likely to win the next. That's not how rugby works.
Twickenham will be another day, another game. Besides ,there are still other games to be played before then - not least Scotland up next in Dublin. That game suddenly feels a lot more exciting.