An interception try from one of the old-heads in the new Ospreys charity jersey, Sonny Parker, had ensured the Ospreys went in at the break with a nine point lead despite twice being reduced to 14 men, but ultimately it was the Saints strength in depth that proved the difference as they managed to survive a difficult night to secure a hard earned win.

Man-of-the-match Matthew Morgan kicked 17 points as he returned to his hometown ground, one of a number of youngsters to catch the eye in an entertaining and physical affair.

The Ospreys enjoyed a bright start, looking to take the game to their more experienced opponents, and they got their reward for the early pressure through a Matthew Morgan penalty after Northampton were penalised for offside.

The Saints had an opportunity to level things up straight away, again after an offside offence, but Ryan Lamb's effort from a central position on the 10m line drifted harmlessly wide of the sticks.

The youthful Ospreys were certainly not overawed, and after a clever dink through put his team in a good position close to the Northampton line, good work at the lineout saw the hosts stealing the Saints ball. Scrum-half Thomas Habberfield tried to snipe his way through, a penalty coming after a Northampton player failed to roll away after hafting his progress, allowing Morgan to put over his second successful penalty of the night.

With 17 minutes gone, a penalty against the Ospreys for coming in from the side, allowed Lamb to slot over the first Northampton points.

It was proving to be a feisty affair, with referee Neil Hennessy having to talk to players from both teams on a number of occasions as tempers frayed, skipper Tom Smith eventually sent to the sin-bin on the advice of the touch-judge after a fracas on the Ospreys 22.

From the resulting set-piece, quick ball from the Saints saw them make the most of the extra man, spinning the ball wide for Ben Foden, coming into the line and drawing the tackle before offloading to Russian wing Vasily Artemyev who crossed for the try, Lamb converting.

As the clock reached 30, great work at the breakdown by Sam Lewis saw the Saints penalised for holding on, allowing Morgan to put over a great kick from halfway to bring the Ospreys back to within a point.

Smith returned to the action as the Ospreys enjoyed a good spell of possession and territory, and another Northampton offence allowed Morgan to nudge his team back in front on 35 minutes.

Good defence then frustrated the Saints as they looked to find a gap, moving it right and then left, Tom Prydie just failing to gather as he looked to intercept on halfway, with a clear run to the line in front of him.

As half-time approached, another off the ball dust-up led to a second Ospreys yellow, this time 19-year old scrum-half Tom Habberfield being sent to the bin. The Saints again looked to take advantage, opting to snub the points and go for the lineout, but fantastic defence saw the Ospreys win turnover ball, driving their way out of trouble to the delight of the home crowd.

With time up and the visitors pressing with their extra man, Sonny Parker read a Saints pass in midfield perfectly, intercepting the pass midway inside his own half and racing through to score under the posts, Morgan rounding off the first half with the conversion, his fifth successful kick of the evening.

HALF-TIME: OSPREYS 19 NORTHAMPTON SAINTS 10

An early penalty against the Ospreys in the scrum saw the Saints again opt for touch, and they got their reward this time when they were able to rumble over the line from close range, skipper Dylan Hartley getting the ball to ground. Lamb's conversion was off target, leaving the score 19-15 to the Ospreys as Habberfield rejoined the action.

It was an entertaining game that was ebbing to and fro, and the Saints looked dangerous when James King lost possession on halfway as the Ospreys looked dangerous. Chris Ashton was able to evade a number of challenges as he edged towards the danger area, a penalty eventually going the visitors way for offside against Aaron Jarvis. Once again the Saints chose to go for the line rather than the posts, but good work on the line saw the Ospreys win the penalty, allowing Morgan to clear.

The TMO was called into action after a similar lineout drive following another decision to put the penalty into the corner, and after a lengthy delay, the decision was try to Hartley, his second of the half, Lamb adding the extras to secure a three point lead.

Northampton were well on top now, and they got their fourth try of the night just minutes later. It came after good pressure up the left, Ashton, Foden and Artemyev all making good mileage before Lamb's clever cross kick changed the direction of the attack, allowing flanker Calum Clark an unopposed run-in, Lamb converting.

Morgan kept the Ospreys in touch with another long-range penalty bringing them back into within a converted try with 15 minutes to go.

Mr Hennessy incurred the wrath of the Ospreys fans once again, pulling back Morgan Allen for a forward pass as the number eight cut a great line through the Saints defence and was set to go over for the try.

A thoroughly entertaining affair was very much still on a knife edge as it moved into the final 10 minutes, and the introduction of a new front row, with Mefin Davies, Duncan Jones and Joe Rees entering the fray, had seen a complete turnaround in affairs, with the Ospreys starting to win penalties at the set-piece.

A run from Ben John cut the Saints defence open but he was pinged after picking himself up to go again after the tackle, the ref judging he'd been held, while up the other end, Scott Armstrong ignored a two man overlap and almost certain try to cut inside, allowing Will Price to halt his progress.

As the Ospreys looked to play their way upfield in search of the score that would level things up, John was penalised for holding on, allowing Stephen Myler to slot over a simple kick that moved his team 10 points clear, making the game safe for the visitors.