All the Ospreys wanted for Christmas was the return of their form, so it is safe to assume Steve Tandy and his players had cause for some satisfaction after downing Northampton Saints at Franklin’s Gardens.

Mind you, they had to survive an astonishing rally that saw Saints claw their way back from 43-8 down with 24 points in eight minutes.

It was a crazy, crazy game in the east Midlands and the relief when Rowan Jenkins achieved a ruck turnover with three minutes left was palpable for the visitors.

There was still time for Hanno Dirksen to be sent off for a high tackle on Juan Pablo Estelles, meaning the visitors finished with 13 men as Rob McCusker had been yellow-carded earlier with Harry Mallinder. Jeff Hassler was also cautioned in the first half.

Alun Wyn Jones of Ospreys breaks clear.

But at the end of it all, the Ospreys had their bonus-point success.

They haven’t haven’t won many games on the road in top-tier European rugby over the years. Indeed, before this game they hadn’t succeeded on their travels at the highest level for 21 games played since 2009.

But those statistics counted for nothing as Tandy’s team got it right for an hour or so at a ground where they had never previously won.

Dan Evans had a terrific game, scoring two tries and taking the man-of-the-match award. What a way for the full-back to celebrate his 100th match for the Ospreys. He and Sam Davies helped give the Welsh region a cutting edge and Kieron Fonotia, Owen Watkin and Hassler were also key in that respect.

The forwards brought a physicality to proceedings that the Ospreys have so often lacked this season, with Dan Lydiate, Alun Wyn Jones, Olly Cracknell, Nicky Smith, Dmitri Arhip and Bradley Davies delivering thunder at rucks and mauls as Northampton struggled to cope.

Jeff Hassler of Ospreys scores try.

For the Ospreys, Evans and Hassler shared four of the tries and Tom Habberfield and Fonotia also got in on the touchdown act, while Davies added 13 points with the boot on an evening when he made a welcome return to form.

The Welsh region dominated the opening half, turning around with a 17-3 lead.

They didn’t help themselves by giving away too many penalties — but they showed huge spirit with the likes of Watkin, Cracknell, Jones and Scott Baldwin holding up home players in the tackle.

Arhip also helped inspire a strong scrum for the visitors, giving Francois van Wyk a tough time throughout the first half.

The first try arrived on 28 minutes and it was a beauty, seeing a purposeful attack end in style when Sam Davies popped up a pass for Dan Evans to touch down. The full-back was playing his 100th game for the Ospreys and his celebration after the try was well merited.

Touchdown number two came just before the break, with Kieron Fonotia flicking on a pass for Jeff Hassler to surge through a gap.

The Canadian had options either side of him, but chose to send the ball inside and Tom Habberfield was able to coast over unopposed.

The Ospreys cashed in during the third quarter with Hassler steaming over after superb work from Bradley Davies and Lydiate, then Davies and Evans combined to send Fonotia across.

Saints were reeling as Evans claimed his second and Hassler did the same.

Sam Davies of Ospreys kicks at goal.

At 43-8 that should have been it.

But then the madness started, with Nic Groom, Rob Horne, Ahsee Tuala and Harry Mallinder touching down in rapid succession. Dirksen’s red card put the tin hat on an evening that was different in every respect.

But at the end of it, the Ospreys are still fighting in Pool 2.

Northampton Saints : Tries: D. Hartley, N. Groom, R. Horne, A. Tuala, H. Mallinder. Cons: H. Mallinder (2). Pen: S. Myler.

Ospreys: Tries: D. Evans (2), J. Hassler (2), K. Fonotia, T. Habberfield. Cons: S. Davies (5). Pen: S. Davies.