Northampton booked a place in the Aviva Premiership play-offs on Saturday with 26-20 win over London Irish at Madejski Stadium.
Chris Ashton was on target with a clinical brace as Saints secured a play-off berth at the expense of Exiles.
London Irish had won their previous three league matches and knew that victory would lift them above Jim Mallinder's side and into fourth spot.
Yet Saints, bolstered by the return of their key England men, proved too strong for them at the Madejski Stadium and moved seven points clear of Toby Booth's side with only one round of matches remaining.
Ashton opened the scoring when he touched down in the 19th minute for a try which fly-half Stephen Myler converted. Irish got off the mark in the 27th minute when Tom Homer booted a penalty and he soon added another to cut Northampton's lead to a solitary point.
However, Myler then replied with three penalties of his own to put the visitors well in control. And Ashton grabbed his killer second in the 57th minute which Myler converted.
Yet Irish rallied hard late on and were rewarded when Richard Thorpe touched down for a try which Homer converted.
The hosts struck again in the 69th minute when Seilala Mapusua went over and Homer converted again to leave the scores finely poised at 23-20 in Northampton's favour.
A penalty from Myler gave Saints some breathing space and they held on for victory, with the losing bonus point little consolation to the Exiles.
For London Irish:
Tries: Thorpe, Mapusua
Cons: Homer 2
Pens: Homer 2
Tries: Ashton 2
Cons: Myler 2
Pens: Myler 4
London Irish: 15 Delon Armitage, 14 Topsy Ojo, 13 Elvis Seveali'i, 12 Seilala Mapusua, 11 Tom Homer, 10 Dan Bowden, 9 Paul Hodgson, 8 George Stowers, 7 Steffon Armitage, 6 Jamie Gibson, 5 Bob Casey , 4 Nick Kennedy, 3 Faan Rautenbach, 2 David Paice, 1 Clarke Dermody (c).
Replacements: 16 James Buckland, 17 Max Lahiff, 18 Paulica Ion, 19 Gary Johnson, 20 Richard Thorpe, 21 Jonathan Joseph, 22 Chris Malone, 23 Darren Allinson.
Northampton: 15 Ben Foden, 14 Chris Ashton, 13 Jon Clarke, 12 James Downey, 11 Paul Diggin, 10 Stephen Myler, 9 Lee Dickson, 8 Roger Wilson, 7 Phil Dowson, 6 Calum Clark, 5 Christian Day, 4 Courtney Lawes, 3 Brian Mujati, 2 Dylan Hartley (c), 1 Soane Tonga'uiha.
Replacements: 16 Brett Sharman, 17 Alex Waller, 18 Tom Mercey, 19 Mark Sorenson, 20 Mark Easter, 21 Stuart Commins, 22 Shane Geraghty, 23 Joe Ansbro.
Referee: David Rose