EDINBURGH (Reuters) -Duhan van der Merwe was the Calcutta Cup hero again when he followed up last year's stunning Twickenham double with a Murrayfield hat-trick that propelled Scotland to a 30-21 Six Nations victory over England on Saturday.

Last season the converted South African scored one of the best individual tries seen at Twickenham for years, then finished off a spectacular Scotland move to seal their third successive win over their fiercest rivals.

They had not claimed four in a row since the 19th century but matched that at Murrayfield as Van der Merwe showed all his attributes with a superb treble.

Scotland were 10-0 down when centre Huw Jones broke through and sent Van der Merwe clear for a simple finish in the right corner.

Ten minutes later he collected the ball deep in his own half, evaded two tackles and fired up the after-burners to score, a body blow for England who had been playing well.

Scotland led 17-13 at the break but, with England having come back from halftime deficits against Italy and Wales, the next score was crucial and it went to Van der Merwe, who scooped up a nicely-judged Finn Russell kick to gallop in for his third.

"I can't believe it to be honest, but I have to thank the boys for giving me the opportunity," Van der Merwe said.

"We had a really good first phase, there was a lot of space open and I knew Finn was going to kick it to me. Lucky for me it bounced in my hands."

Scotland coach Gregor Townsend has overseen five wins and a draw in the last seven Calcutta Cup clashes.

"You have to celebrate these moments, especially when you have a trophy in the dressing-room," he said.

"Duhan was great today. He saw the opportunities and went for it. I think the first try was really special in that we didn't have much ball, we weren't in England's half very often."

AGONISING DEFEAT

Scotland's second win of the championship followed their agonising last-gasp defeat by France.

"To come back and then score 30 points shows what this team is capable of," Townsend said. "There is improvement to do and we want to get to the final week with an opportunity to still be in the championship.

"We are not getting ahead of ourselves. I’ve been here with Scotland for nearly 10 years now, and we’ve been beaten by 60 points down at Twickenham or by a point up here. It’s been nice being on the other side of it for the last few years."

England coach Steve Borthwick relied on his regular line that his team were still learning.

"We have to give credit to Scotland, it was a very strong performance," he said. "You saw a Scotland team that have been together a good number of years and are clear what they are trying to do against an England team that are tying to develop," he said.

"I thought the guys started well but the second quarter is where our errors went up and Scotland were able to score too easily, you can't let them do that," Borthwick added.

"Today was not good enough. Now we have two weeks to build to Ireland (at Twickenham) and we will make sure we are better."

(Reporting by Mitch Phillips, editing by Ed Osmond)