The Ospreys scored four tries in the Liberty Stadium rain to secure a bonus point win that moves them up ahead of Saracens to second in Champions Cup Pool 2 with two games to play.
Back-to-back bonus point wins over the Saints have transformed the face of the pool, with double European champions Saracens losing both of their double header games against Clermont Auvergne. Sarries are next for the Ospreys in the competition, visiting the Liberty Stadium next month.
The hosts led from the third minute, Dmitri Arhip with an early try and two penalties from Sam Davies giving them an 11-0 half-time lead.
The Saints rallied at the start of the second half to cut the deficit to three points before the Ospreys blew the visitors away, a Rhys Webb double and Justin Tipuric try sealing the win, with Davies finishing on 12 points.
Webb’s brace saw him overtake Tommy Bowe (36) and go level with Nikki Walker (37) in second place on the all-time try scoring list for the region.
The Ospreys came racing out of the blocks and were in front with barely two minutes played.
It was Ben John who gave the team go forward on halfway, taking the ball off Owen Watkin and carrying strongly. Tom Habberfield provides good support before it was worked wide to the right where Arhip was able to bundle his way over from five metres out.
The angle proved too much for Davies but it was just the start the Ospreys wanted.
Despite the Ospreys probably shading the first quarter of an hour it was the Saints who should have scored next, Piers Francis with the break, spotting a huge overlap on the right. It seemed a simple case of moving the ball through the hands for the score, Ahsee Tuala hugging the touchline, but John put in a great cover tackle on Harry Mallinder, forcing the ball to go forward into touch as he tried to find his winger.
Having opted for a scrum inside their 22 rather than a line-out, the Ospreys were penalised at the setpiece, allowing Saints to lay camp on the line with a series of rolling mauls, a huge physical effort from the home pack eventually clearing the danger, driving their opponents back 15m and forcing the knock on, to huge roars of approval from the crowd.
Sam Davies stretched the lead to eight points in the 25th minute, making no mistake with a long-range effort from a central position 42m out.
The Ospreys pack were dominating the scrum, winning a number of penalties across the field, and it was one such offence that allowed Davies to take the score to 11-0 at the half hour mark.
Northampton came back at the Ospreys, a Jeff Hassler high tackle allowing the visitors to set up camp inside the home team’s 22. The Saints were unable to find a way through in the face of relentless defence, Sam Davies eventually able to steal possession under the posts, allowing Dan Evans to clear.
As half-time approached that was very much the story of the game, Saints pressing without getting anywhere, the Ospreys defence comfortably holding firm.
HALF-TIME: OSPREYS 11-0 NORTHAMPTON SAINTS
The Ospreys continued to dominate at the scrum after the break, continuing to win penalties, but the lineout remained their Achilles heel and not for the first time they turned over possession when well placed five minutes into the second half.
This time it was to prove costly, the Saints advancing to the Ospreys 22 where a perfectly placed cross kick found Tuala on the Northampton right who palmed it down for Mallinder to finish it off in the corner.
Francis missed with the conversion but just three minutes later he had a simple kick in front of the posts, the Ospreys pinged on the floor, to make it a three-point game.
The response from the Ospreys was perfect, grabbing their second try of the afternoon after a prolonged spell of pressure in the Saints 22, great work from Scott Baldwin and Tom Habberfield on the right to keep the move alive under pressure before it came back infield where Webb sniped his way over from close range in trademark fashion.
The conversion from Davies was good and the Ospreys led by 10 with just over 20 minutes left.
Some lovely interplay between backs and forwards then took the Ospreys to within metres of the line, Hassler and Olly Cracknell carrying powerfully, but Justin Tipuric couldn’t hold Webb’s pass.
The Ospreys were on top and try three arrived in the 65th minute, a wonderful off the cuff team score that saw Evans scything his way through the Saints midfield from inside his own half, finding Watkin who in turn fed Tipuric who finished the move off in style.
Davies converted and just a couple of minutes later the bonus point was in the bag, intense pressure on the line seeing Tipuric stopped just a metre out before Webb picked up and stretched over the bodies on the floor to score his second of the day.
With Davies’ conversion again good, the scoreboard showed a very healthy 32-8 lead for the home team, which meant it was over as a contest.
Saints had the final say, Rhys Marshall driving over from close range and Mallinder converting, but that was little more than consolation as the Ospreys celebrated a big win.