A rampant pack performance in the second half brought Edinburgh's seven-game losing streak to an end last night as they humbled the reigning RaboDirect PRO12 champions on a chill Murrayfield evening.

Led brilliantly by captain Sean Cox, who had admirable lieutenants in the shape of Stuart McInally and John Yapp, Edinburgh turned the game on its head after the break, wiping Ospreys for possession and territory as they turned a five-point deficit into a precious 10-point win, only their third competitive victory of the season.

Fly-half Gregor Hunter scored all but five of their points, but the heroes of Edinburgh's hour were mostly in the pack. Tightening up after an edgy first 40 minutes, they played with measured ferocity after the turn and demolished their opponents in the scrum.

"Once the rustiness was out of the side we gelled well in the second half," said Cox. "Coming off five losses in the PRO12 and another two in the Heineken Cup we knew how important this game was."

Yet with Ross Ford back in the side, it had been a worrying portent that Edinburgh failed to secure their very first lineout, after which McInally, another returnee from Scotland duty, caused real alarm among supporters when a rash pass was intercepted by Ospreys fly-half Matthew Morgan, who hared off with the ball. However, McInally's blushes were spared when Richie Rees pulled off a brilliant tap tackle to deny Morgan a score.

Rees went from hero to zero soon afterwards when some stroppy behaviour to deny the Ospreys a quick lineout gave the Welsh side a penalty instead, duly converted by Morgan for a 3-0 lead after 15 minutes. Parity was restored seven minutes later when Hunter clipped over his first kick for Edinburgh.

At that stage, Edinburgh coach Michael Bradley must have been more concerned by the pattern of the game than with what was happening on the scoreboard. Ospreys seemed to be able to hold on to the ball for lengthy periods, recycling efficiently and quickly, while Edinburgh were laboured in possession and usually turned it over after just a few phases.

And yet, in that maddening way they have, Edinburgh then contrived a score with some sublime play. Morgan had just nudged Ospreys 6-3 ahead with his second penalty when Edinburgh broke right from a ruck near the Welshmen's 10m line. The move came alive when Dougie Fife added pace down the touchline, and quick passing took the ball through the hands of Hunter and Rees before Willem Nel finished off with a try, his first for the club.

As half-time loomed, a Rees kick was charged down near the Edinburgh 22 and Ospreys churned through the phases again. Edinburgh, on the back foot, tried gamely to hold them out, but Ospreys kept inching forward and their pressure was rewarded when Morgan darted over for a try and a 13-8 half-time lead.

Things looked distinctly brighter for Edinburgh three minutes after the turn when a collapsed scrum brought a yellow card for debutant Ospreys prop Owen Williams. Hunter missed the penalty, but with Edinburgh firmly in the driving seat against under strength opponents another opportunity came along soon afterwards and Hunter duly nailed the kick to cut the gap to two points.

A minute before Williams' return, yet another Ospreys scrum caved in and yet another Hunter penalty sailed between the posts to put Edinburgh back in front. As the energised home forwards moved up through the gears, the penalties came thick and fast, and Hunter consolidated the lead with a couple more successful kicks around the hour mark.

Yapp had been leading most of Edinburgh's charges, so it was a distinctly ironic twist that his departure, in the 68th minute, brought perhaps the loudest cheer of the evening. Even he must have understood, though, as the man who replaced him was Allan Jacobsen. When he announced his international retirement on Monday Jacobsen had reaffirmed his commitment to Edinburgh, and it was clear that the Murrayfield crowd have lost none of their affection for him.

The Welsh side lost another player when flanker Sam Lewis was sent to the sin bin in the 67th minute. Hunter closed out the match with his sixth penalty of the evening – again, won in a scrum – to deny Ospreys a bonus point and bring Edinburgh's sorry run to an end.