Wales Sevens international Will Harries grabbed a hat-trick of tries as the Dragons produced a memorable second half display to dent Edinburgh's Magners League play-off hopes.

Paul Turner's side crossed the Scots' whitewash seven times in total to keep their own chances of reaching the semi-finals alive.

Edinburgh made their way down from Scotland on Saturday by road due to the Icelandic volcanic ash situation that has shut airports across Europe - and despite the long journey, Rob Moffat's men were keen to get the win to maintain their title push.

The sixth-placed Dragons can still make the play-offs themselves after this triumph but have been buoyed by the Cardiff Blues' win over the Scarlets on Saturday that ensured Heineken Cup rugby for them next season.

With Wayne Evans, Ashley Smith and Harries scoring a try apiece, the Dragons went into the break with a 20-14 buffer.

The lead had changed hands four times by then. Scrum half Wayne Evans opened the scoring in the tenth minute when he burst away for the corner, after taking a terrific offload from prop Hugh Gustafson who made the initial incision.

That lead did not last long as, almost straight from the restart, Edinburgh's Scotland-capped fly-half Phil Godman picked up a loose ball and fed flanker Alan MacDonald to go over under the posts.

Godman's conversion put Edinburgh 7-5 ahead but a blast through the middle from 25 metres out by centre Smith restored the Dragons' lead.

Evans converted as regular place-kicker Jason Tovey was being treated for a knock to the had. The talented numbr 10, who was being watched by Wales coach Warren Gatland, had to be replaced by James Arlidge.

As play resumed, Edinburgh were back on the offensive. MacDonald was superbly tackled in the corner and Godman nearly scored from the ruck but was brilliantly wrapped up as he went over the line by Dragons flanker Gavin Thomas.

It did not help the Dragons' cause either that loosehead Gustafson was sin-binned for dropping a scrum on his own line which, moments later, led to referee James Jones awarding a penalty try that gave Edinburgh a 14-12 lead.

Arlidge restored the home advantage with a penalty and winger Harries increased it to 20-14 with a well-executed try, following good work by Gustafson and Richard Fussell, on the cusp of half-time.

It got even better for the Dragons after the break as Edinburgh missed numerous tackles and created little in the way of attacking play as the hosts took control.

Arlidge added another penalty, four minutes into the second half, and the pacy Harries collected two more tries before the hour mark to complete his hat-trick.

Gavin Thomas teed up his second as his pass gave Harries enough space to squeeze outside Mark Robertson and score.

The industrious Thomas provided the assist again, in the 56th minute, with his pass back inside sending the 23-year-old on his way to the try-line.

Edinburgh had a try ruled out by a push by winger Tim Visser and were now 21 points in arrears.

But, with some renewed vigour in the final quarter, they got themselves back in the game as centre Ben Cairns went under the posts, with Godman's conversion meaning they could draw with two more converted tries.

However, any revival was killed off completely when Dragons flyer Richard Fussell grabbed a sixth touchdown and full-back Martyn Thomas scored a spectacular 60-metre effort.

To their credit, Edinburgh fought to get something out of the match and managed it when Lions hooker Ross Ford came out of a pile of bodies with the ball to secure a bonus point for his side.

Edinburgh are now in fifth position, two points away from the play-off zone, with a home fixture against a struggling Ulster side next on th agenda.

Speaking after the reversal to the Dragons, Edinburgh coach Rob Moffat said: "You cannot defend like that - we gave away some really soft scores. You can't miss as many one-on-one tackles as we missed today and expect to win.

"Defensively we looked uncomfortable when they had the ball and, in fact, whichever team had the ball looked dangerous, so even when we trailed 28-14 in the second half I felt we'd still score another try or two.

"We're in the position we are in the league because we've lost our last two games and we've a lot of improving to do, especially in defence, for the Ulster game at Murrayfield next Sunday.

"But there's no point in feeling sorry for ourselves. We'll aim to rectify things for next Sunday."