Scotland head coach Gregor Townsend says the Calcutta Cup win over England was the biggest of his coaching career.
His side produced one of the great Scottish performances to earn a 25-13 win over the back-to-back Six Nations champions at Murrayfield on Saturday.
Townsend has masterminded wins over Australia - home and away - and France, and won a Pro12 title with Glasgow, but says the England win tops the lot.
"From a coaching perspective, that's the biggest win," he said.
"We came very close to beating the number one team in the world [a narrow loss to New Zealand in November]. Now we've beaten the number two team.
"I think the first half here and the first half of the New Zealand game were similar, in our intent to play where we believed we would get success. The difference was we finished off opportunities.
"It wasn't the complete performance. But the way we defended in the second half, especially in the last two minutes, when the clock ticked to 80 and we were still defending - I'm very proud of the players' efforts."
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Scotland had not beaten France and England at home in the same year since 2006, the year they enjoyed their highest Six Nations finish of third place.
In the past 12 months they have also beaten Ireland, Wales and Australia twice, and with away games against Ireland (on 10 March) and Italy (on 17 March) to come, Townsend believes there is still more to come from his team.
"We want to improve," said the former fly-half, who is in his first Six Nations campaign as head coach.
"It is about progress. Finding a way to win but getting better.
"That was much more like the standard of performance we put in in November. We still weren't at our best. That was getting closer. We need to improve."
Townsend paid tribute to Finn Russell, the fly-half who was much maligned for his performances against Wales and France, but responded with a scintillating display which earned him the man-of-the-match award.
"Finn was outstanding in November, taking on the best teams in the world. He was world class.
"He hasn't had the best of starts to the Six Nations. But he played like he did in November.
"We ask a lot of our 10s, they have to be brilliant every time. There will be errors.
"The pleasing thing was seeing Finn play the rugby we know he can play. Putting passes in space, tackling well, making good decisions.
"He created a lot of space for us and he can kick on from here. Every player goes through periods where they've not got into the game as quickly as they want. He was very well prepared for today."
'The team was world-class, not just an individual'
With praise for his performance coming from all corners, Russell was keen to share the plaudits with his team-mates.
"I couldn't have played like I did today without the boys round me giving me the support and knowing their game-plan as well as I did," said Russell, who will leave Glasgow at the end of the season in a big-money move to French side Racing 92.
"I think today the team was world-class, not just an individual.
"It's not quite settled in yet. It's an experience I've never had and a feeling I've never had.
"It was amazing to go out and beat England. Not even just beat them but the way we played. We played so well and executed the game-plan, not as well as we could, but well enough.
"There are still things to work on but it was a pretty good performance."
Russell said the criticism for his performances in the 34-7 defeat by Wales and the 32-26 win over France - he was substituted after 65 minutes - did not play on his mind.
"That's sport, that's the game we play in. You get the highs and the lows," said the 25-year-old.
"Last week we won and some people said I wasn't so good and against Wales the whole team got a slating.
"We've managed to bounce back against France and obviously today. That's the job we're in. You've got to accept the highs and the lows and we'll enjoy the high."