Scotland assistant coach Jonathan Humphreys admits the Dark Blues have surrendered their set-piece surprise factor after their cheeky line-out move paid off against Ireland.

The Scots left Joe Schmidt's men looking silly on Saturday when Alex Dunbar snuck into a first-half line-out before diving over for his side's third try.

While the Glasgow centre celebrated, the Irish were left scratching their heads.

Vern Cotter's men now travel to Paris to face France this weekend in confident mood after kicking off their RBS 6 Nations campaign with a 27-22 win.

But forwards coach Humphreys, who was credited with conjuring up the gutsy move by Cotter, reckons Les Bleus will not be so easily fooled.

He said: "People haven't realised we tried that move against Tonga two years ago and Alex dropped the ball. They know it now though.

"We identified the possibility that it could work against Ireland. We came to the team run on Friday and Jonny Gray said, 'Shall we go through that move?'. But I said, 'Nah'.

"So in reality Jonny should be taking the credit for persevering and saying ,'I want to do that move on Saturday'. I'll give it to him.

"Do we expect teams to pay a bit more attention to what we're doing at line-outs now? Yeah.

"These are moments in the game that either make you look great or they don't. But I don't think your game can be based just around that.

"It's got to be based around a lot more than that. We've got a lot of pace in our side and move the ball well, so that's probably got more basis in what we're trying to do right now."

The fact Scotland were able to see off a side that has beaten South Africa, Australia and New Zealand within the past seven months is even more impressive given their scrum struggles during their opening 40-minute blitz.

Loosehead Allan Dell found himself pushed around early on by Ireland's Tadhg Furlong while his 21-year-old colleague Zander Fagerson was also pinged as the visitors won the first three contests at Murrayfield.

Scotland secured their first victory over Ireland in four years (Getty)

Cotter's young props eventually got their act together but Humphreys knows they face an even bigger task taking on the muscle-bound French front-row.

"We understood that Ireland would be a threat at the scrum," he said. "The stuff we planned we didn't execute at the start of the game as well as we would have liked.

"What was pleasing was that the boys solved the problem. There was a scrum in the second half five metres from our line where we managed to turn things around and were dominant in that area.

"It is a huge work in progress. We have fantastic athletes in the front row who are learning. But they give us so much more as a team.

"But we know we are in for a massive battle in that area this Sunday.

"With France, what you see is what you get. They're huge. They are a lot better than they've been for a long time - a lot more creative. We are expecting them to be pretty powerful.

Scotland head into their next game against France as favourites (Getty)

"They'll come at us with all that but our prep is good. We understand the threat and it is about making sure we go out there and don't give them what they want."

Humphreys has no lack of faith in Fagerson and Dell but he cannot afford to be too hard on them when they do slip-up.

The two men who have formed the corner-stones to the Scottish pack in recent times, Alasdair Dickinson and WP Nel, are currently out injured, and while the former may make a return before the end of the Championship, Scotland are going to have to rely on their fresh-faced forwards.

For example, Fagerson was required to play the full 80 minutes on just his fourth Test start and may be in for a similarly arduous shift this weekend.

But Humphreys said: "We are confident. The boys who came in during the autumn went through a huge learning experience. This is not the best tournament in the world to learn, but we feel we have the depth to do that.

"They are following on from two fantastic performers who have been really good for us over the last 18 months.

"They understand the responsibility they have but we are delighted with them. What they give us outside the scrum is phenomenal, more than probably anyone else from the opposition playing.

"Zander is phenomenal. He is going to be the mainstay of this team for a long, long time. Hopefully the future will be bright for us in this area."