Edinburgh blew their chance to move to the top of the Magners League when a first half of mind-numbing boredom and incompetence gifted victory to their Welsh opponents, the first time the visitors have won in Scotland for more than two years.

Everything that Edinburgh had done well a week earlier in defeating a near full-strength Munster side was missing from this showing until it was too late to rescue the position. There was no real urgency to their play, the handling was dreadful and to rub injury into the insult, they finished the game by presenting Andy Robinson, the Scotland head coach, with problems ahead of the autumn internationals.

It had all started before the kick-off when both Alan Macdonald and Chris Paterson pulled out, the former with a calf strain, the latter with a foot infection. In both cases the decision not to risk them was presented as being more a precaution than anything else, but Paterson in particular would be a huge concern.

Worse followed when Ben Cairns, widely expected to fill the outside centre berth in the Scotland side against Fiji, limped off midway through the first half with a knee problem and it got even more worrying when Phil Godman finished the game hobbling round the field. Cairns will be assessed later this week, Godman himself did not think the damage was too serious but he will also have to wait and see.

None of which had anything to do with the appalling handling that ruined Edinburgh’s chances of moving into the kind of lead they might be able to exploit in the hunt for the bonus point that would have put them top of the Magners League at the international break. True, the weather did not help with a steady drizzle falling throughout the game on an already sodden pitch, but Newport Gwent Dragons did not find it nearly as much of a problem as the Scots.

With the Dragons also winning the first-half kicking game, they had the majority of pressure and took full advantage with James Arlidge kicking all three of the penalty chances to move his side into a nine-point lead at the break that owed much more to the Edinburgh’s incompetence than anything they had done constructively.

“It was a poor half, unacceptable,” Rob Moffat, the head coach, said. “We made a lot of basic mistakes, there were too many forced balls in contact and too many went down. You have to wonder why we played so badly in the first half, if we had played in the opening period the way we did after the break, we would have won.”

The problem was that when Edinburgh tried to play territory, they were outgunned by the greater range of the Welsh region’s kickers, with Arlidge and Jason Tovey at full back pinning the home side into their 22. When Edinburgh did try to run it, they could not hang on to the ball long enough to create any sort of pressure. It was a miserable spectacle.

Edinburgh did manage to pick up the pace after the break, showing a lot more urgency than in the first half and felt they should have had greater reward when they won a series of penalties on the visitors’ line, elected to take scrums at all of them but did not see any suggestion of a sin-bin or penalty try from Alan Lewis, the referee, before they won a penalty under the Dragons posts and took the points through Godman’s boot.

That ushered in Edinburgh’s best period of the game and eventually they managed to produce the try they needed, with Ally Hogg making the break through the middle and for once the team’s handling held together long enough for them to put Andy Turnbull over in the corner.

It was too wide out for Godman to convert, however, and he also missed a drop goal attempt to pinch the result. Fittingly, it was the Dragons who finished in the Edinburgh half, and a home knock-on that finally ended the game.

Scorers: Edinburgh: Try: A Turnbull (66min). Penalty goal: Godman (56). Newport Gwent Dragons: Penalty goals: Arlidge 3 (16, 22, 28).

Scoring sequence (Edinburgh first): 0-3, 0-6, 0-9 (half time), 3-9, 8-9.

Edinburgh: S Jones; J Houston (rep: A Turnbull, 41min), B Cairns (rep: M Robertson, 31), N De Luca, T Visser; P Godman, G Laidlaw (rep: M Blair, 57); A Jacobsen (rep: K Traynor, 64), R Ford (rep: A Kelly, 57-79), G Cross, S Turnbull, S MacLeod, S Newlands, R Grant, A Hogg (capt).

Newport Gwent Dragons: J Tovey; A Brew, T Riley (rep: R Gomer Davies, 68), M Watkins, R Fussell; J Arlidge, W Evans; H Gustafson (rep: P Palmer, 73; rep: J Harris, 75), S Jones (capt; rep: D Goodfield, 59), P Palmer (rep: P Bracken, 67) , R Sidoli, A Jones, H Macdonald, G Thomas, G Webb (rep: T Falatau, 71).

Referee: A Lewis (Ireland). Attendance: 2,066