The result was sweet revenge for the Dragons' narrow Heineken Cup win at Murrayfield earlier this month but leaves Dragons coach Chris Anderson facing his first major problem since taking over following their defeat at Munster last weekend.
What will make matters worse is that the Dragons appeared to cruising on 47 minutes when skipper Jason Forster dived over from close range against 14-man Edinburgh. Warlow added the conversion following his first-half penalties to open a 13-0 lead while Edinburgh's frustration boiled over with Laney and his own prop Joel Brannigan almost coming to blows behind the try line. Things were looking good.
But if Anderson was hoping his team would finally move up through the gears after a cumbersome first-half, his players let their foot slip off the clutch. Tired and lethargic, the Dragons lacked any bite in attack. Worse still, they began to miss their tackles.
Jamie Ringer and Richard Bryan both let replacement Rob Dewey slip through their grasp, Laney moved the ball wide for Derrick Lee to score in the corner on the hour. Ten minutes later and Edinburgh, galvanised by a wave of replacements, took the lead. Again the Dragons allowed their opponents to break through, No 8 David Callam making it count. Laney's conversion put the visitors a point ahead.
That finally sparked a response from the Dragons and when Warlow kicked his third penalty, four minutes later, it looked as if they had salvaged the victory. It even looked as if they could have stretched that lead when Kevin Morgan almost put Gareth Wyatt with a slide rule pass.
Yet Edinburgh never gave up and in fact played more of the rugby when the Dragons strayed offside in the middle of the field, there was only time for Laney's late winner.
Dragons: K Morgan; G Wyatt, S Tuipulotu (J Bryant, 63), S Winn, N Brew; C Warlow, G Baber; R Snow (A Black, 63), J Richards (K Crawford, 70), C Anthony (R Thomas, 63), I Gough, P Sidoli (R Beattie, 63), J Ringer, R Bryan (G Chapman, 80), J Forster (capt, R Oakley, 75).
Try - J Forster. Con - C Warlow. Pens - C Warlow (3)
Edinburgh: D Lee; C Joiner, M Di Rollo, P Boston (P Godman, 66), S Webster (R Dewey, H-T); B Laney, R Lawson; C Smith, A Kelly (D Hall, 63), J Brannigan (A Dickinson, 63), F Pringle (A Strokosch, 66), A Kellock, T Blackadder (capt), D Callam, S Cross (A Dickinson, 34, A McDonald, 58).
Tries - D Lee, D Callam. Cons - B Laney (3).
Referee: C Stanley (Ireland).