Saints kick-started their Heineken Cup campaign with a crucial 27-16 win over Ospreys at Franklin’s Gardens.
Tries from Samu Manoa, Christian Day and Ben Foden secured the victory, which got Jim Mallinder’s men back on track after the opening-day defeat at Castres.
Wales fly-half Dan Biggar, who was sin-binned late on, responded with 16 points but Ospreys continued their woeful away record in the Heineken Cup.
The Welsh side have now won just two of their past 19 games on the road in the competition and will know they need a miracle to make it out of Pool 1.
Saints, though, head into December’s decisive double-header against Leinster with five points to their name after a high-tempo first half showing set them up for the win against Ospreys.
They may feel they could even have taken five points from the Gardens encounter as they pushed for a fourth try towards the end.
But a win was the minimum requirement, and Courtney Lawes showed his team’s desire from the off, smashing into Tom Habberfield from the kick-off and immediately winning the ball for Saints.
They took advantage of the possession, winning a penalty that Myler easily slotted to put his men 3-0 up.
It was the fast start Saints needed as they scrapped hard at the breakdown to strangle their opponents.
The forward battle, with Alex Waller facing Lions star Adam Jones and Mike Haywood, a blood replacement for Dylan Hartley, was also intriguing - and Saints were on top.
A good push five metres out bamboozled the Ospreys defence and No.8 Manoa picked up from the back to ease over the line unchallenged.
Myler made it 10-0 with 14 minutes gone before Hartley returned to the ranks and Saints continued to push on.
Ospreys did get some respite as Salesi Ma’afu was penalised at the breakdown and Biggar got his side on the board.
The No.10 was on target again soon after as his forwards squeezed a penalty out of a scrum on halfway and Saints’ lead had been narrowed to just four points.
The away side’s recovery was soon crushed, though, as more fine work at the breakdown, particularly from Tom Wood, helped set up a try out wide for Day.
Myler made it 17-6 with a well-struck conversion from wide left before some fine covering work from Foden ensured Ospreys didn’t strike back immediately.
Saints were dominating the play, but the men in black were looking sharp on the break, with only the bounce of the ball preventing Richard Fussell grabbing his side’s first try.
Northampton held a 17-6 lead at the break, but Ospreys emerged with the bit between their teeth at the start of the second half and Foden was needed again to stop Alun-Wyn Jones as he headed for the line.
But Saints weren’t to escape for long as the pressure built up and Biggar ensured the home side cracked by finding his way over the line.
The fly-half added the extras to cut Saints’ lead to four and Myler missed the chance to extend that advantage, firing a penalty wide from halfway.
The home side needed a spark, something to get them back in the ascendancy, and they found it as the forwards mounted a charge and Day fed Foden, who scored out wide.
Myler brilliantly slotted the conversion to make it 24-13 and Saints had their sights set on the four-try bonus point.
But Ospreys responded by winning a penalty from the scrum, Biggar kicking superbly again, before a charge from the impressive Lawes at the other end was halted five metres out.
Saints soon had more points, though, winning a penalty and opting to go for the safety of the posts, with Myler making the kick.
With an 11-point lead, Saints had the chance to turn up the heat in the hunt for the bonus point and they pushed Biggar into seeing yellow.
But, despite huffing and puffing, the home side couldn’t blow the Ospreys door down and were forced to settle for four points.
Saints: Foden; Elliott (K Pisi 75), G Pisi, Burrell, North; Myler, L Dickson (Fotuali’i 63); A Waller (E Waller 70), Hartley (c) (Haywood 75), Ma’afu (Denman 58), Lawes, Day, Dowson (Clark 56), Wood, Manoa (van Velze 56).
Replacements not used: Wilson.
Ospreys: Fussell; Hassler, Bishop (Lewis 70), Beck (Morgan 72), Walker; Biggar, Habberfield; Bevington (D Jones 63), Hibbard (Baldwin 70), A Jones (Jarvis 54), A-W Jones, King, R Jones (Ardron 54), Tipuric, Bearman (Allen 48).
Replacements not used: Tebaldi.
Referee: Alain Rolland (Ireland)