Possession may be nine points of the law, but nine points was not enough to win this rugby match for the Scarlets thanks to two moments of magic from left-wing Duhan van der Merwe.

The home side just had three penalties to show for dominating territory and possession, as a sterling rearguard effort by the Edinburgh defence managed to keep their line intact.

The figures were stark as the Scarlets had three to one dominance of possession, more than a third of the game spent inside the Edinburgh 22.

“The second half we didn’t have the ball, we coughed it up and spent a huge amount of time in our own 22,” admitted Edinburgh head coach Richard Cockerill.

“Our defensive display across the board was very good. Callum Macrae, our defence coach, is a tenacious man and he works very hard at it. He should take the plaudits today because the defence won the game for us.

“It is a massive win. They are a good side, they are well coached, we were both missing lots of guys for obvious reasons. We have played them twice, we have taken nine points and they have one, which in our conference is pretty big.

“The conditions made it hard work but we live in Scotland, it rains a lot and it’s windy. You have to deal with it, you have to dig in, it wasn’t pretty, they were unlucky at times but you ride your luck and we will keep taking it.”

The game was in doubt before kick-off because of Storm Dennis, but the rain reduced from heavy to steady as kick-off approached and the pitch was in surprisingly good condition.

The rain caused problems, but it was an unpredictable wind which was the greater difficulty for the players – though in truth conditions were better than in Murrayfield for the Calcutta Cup.

Experience should count for a lot when the conditions are hard and Edinburgh had the advantage in that area with 10 internationals on the field and six released

from the Six Nations Scotland squad, compared to six and two respectively for the Scarlets.

Edinburgh also went into the game knowing that victory would send them back to the top of the table while also preventing the Welsh team from going above them.

It was possible, if difficult, to play some rugby as Edinburgh showed early on. A kick was collected by Nick Haining who ran it back and his off-load freed Matt Scott who put van der Merwe into space.

The South African, who qualifies for Scotland through residency in the summer, used his support runners as decoys to go 50 yards for the opening try. Jaco van der Walt converted from in front.

The Scarlets were the dominant side for most of the first half, but only had a couple of Dan Jones penalties to show for it as the Edinburgh defence held firm inside their 22.

Edinburgh missed opportunities to relieve that pressure by not judging the wind correctly, van der Walt twice missing touch from penalty punts, among the many examples of missed kicks.

However that man van der Merwe was not to be denied and just before half time he came bursting through the defence close to a scrum and was able to put Scott through for the try. Van der Walt again converted.

The first score of the second half was always going to be crucial and that went to the Scarlets as Jones notched another penalty for an off-the-ball tackle by Edinburgh prop Pierre Schoeman.

Van der Walt continued to mis-read the conditions, in a game where the control from outside half was always going to be vital. Unsurprisingly Cockerill made the change at 10 with Hickey coming on after 57 minutes.

The Scarlets were trailing by just five points and camped inside the Edinburgh 22, dominating territory but unable to make it the last couple of

metres over the line.

With man-of-the-match Bill Mata to the fore in defensive duties, Edinburgh held firm under immense pressure. He put in a try saving tackle on Scarlets wing Steff Evans, while also playing a crucial role on the line in preventing South African Uzair Cassiem getting over.

Replacement flanker John Barclay was also part of a crucial turnover on the line at a ground where he spent five seasons contributing such moments to the home side.

The conditions made it hard for the Scarlets to attack with width, while the visitors were strong when the attacks were narrow. It was enough to secure a fifth victory in a row over the Scarlets and Edinburgh, along with Munster, will think they are beginning to open up a useful gap at the top of the Conference.

Scorers, Scarlets – Pens: Jones 3.

Edinburgh – Tries: van der Merwe, Scott. Cons: van der Walt 2.

Edinburgh: D Hoyland; E Sau, M Bennett (G Taylor 68), M Scott, D van der Me rwe; J van der Walt (S Hickey 57), H Pyrgos (N Groom); P Schoeman (J Bhatti 71), D Cherry (M Willemse 28), WP Nel (P Ceccarelli 62), L Carmichael, G Gilchrist (F McKenzie 51, then J Barclay 58), N Haining, L Crosbie, B Mata.

Scarlets: A O’Brien; R Conbeer (P Asquith 59), S Hughes (Capt), K Fonotia, S Evans; D Jones, K Hardy (D Blacker 76); P Price (R Evans 40), T Davies, W Kruger (J Sebastian 59), L Rawlins (T Ratuva 48), S Lousi (S Cummins 68), A Shingler, U Cassiem.

Referee: F Murphy (IRFU). Att: 5,639.