England hopeful Chris Ashton crossed for three scores as Northampton upset Newcastle 28-8 at Kingston Park on Friday.
The former Wigan rugby league back crossed for a try in the first half followed by a brace in the second 40 minutes, with fly-half Shane Geraghty kicking three penalties and two conversions for the visitors.
Newcastle's try came at the end of the opening stanza from wing Tom Biggs, with stand-off Jimmy Gopperth kicking a solitary penalty for Steve Bates' side.
The Falcons made just one change in personnel from the side that won at London Irish last weekend with Biggs coming in on the wing as Charlie Amesbury moved to full-back to replace the injured Alex Tait.
Northampton, meanwhile, had captain Dylan Hartley back from England duty with Geraghty and Courtney Lawes also back in the starting line-up following their stints with the national squad, but were without Bruce Reihana, the New Zealander's place on the wing being taken by Joe Ansbro.
The 6,522 strong crowd, Newcastle's best of the season to date, were on their feet during the opening exchanges as Ashton's loose tap-back from a Geraghty chip put the Saints in trouble.
Gopperth was first to the ball and he hacked ahead but Ashton recovered well to beat Falcons centre Tane Tu'ipulotu to the touchdown as the ball rolled into the in-goal area.
But Ashton showed his finishing ability in the seventh minute as the Falcons were caught napping when Northampton took a quick tap in front of the sticks and Geraghty's floated pass put the winger over, although the fly-half failed with the tough conversion.
Gopperth got the Falcons on the board with a 15th minute penalty, but Geraghty, looking to bounce back after losing his place in the England side that faced New Zealand, replied in kind seconds later when the hosts came in from the side at a ruck having ceded possession at the restart.
Gopperth then missed a chance to knock over a second penalty when he dragged a 40 yard effort wide after Saints were caught offside.
Despite that miss the Falcons were enjoying a period of territorial dominance, and the breakthrough finally came after the hosts had turned down the chance to go for goal on three occasions as they sought a try.
Amesbury entered the line from deep off Gopperth's pass and a lovely line of running from James Hudson saw the second row offload to put Biggs over in the corner. Gopperth hit the post with the conversion after slipping as he struck the ball to leave the score 8-8 at the break.
But the crowd's delight at that rousing end to the opening half was dampened when scrum-half Micky Young's fierce pass flew over the head of Amesbury to gift the visitors a five metre scrum.
The Falcons were made to pay for that error when, after several phases, prop Soane Tonga'uiha offloaded to allow Ashton to sprint over for his second try of the evening after 50 minutes, converted by Geraghty.
Geraghty had a chance to extend the lead shortly after but his horrible strike saw his penalty fly wide, but 23-year-old made amends when the Saints scrum forced a penalty after a powerful surge close to the Newcastle line.
The power of the Saints pack was stifling Newcastle, with the rolling maul proving a particularly effective weapon, as they dominated territory and possession and Geraghty added his third penalty to extend the lead to 21-8, and put a seal on the win, in the 67th minute.
A miserable second half for Newcastle was then compounded as Young was sretchered off after prolonged treatment in the final minute, and when play restarted Geraghty's cross-kick gave Ashton the simplest of finishes to complete his treble, Geraghty landing the touchline conversion with the last kick of the match.
Tries: Ashton 3
Con: Geraghty 2
Newcastle: 15 Alex Tait, 14 Charlie Amesbury, 13 Rob Vickerman, 12 Tane Tu'ipulotu, 11 Tom Biggs, 10 Jimmy Gopperth, 9 Micky Young, 8 Adam Balding, 7 Will Welch, 6 Tim Swinson, 5 Mark Sorenson, 4 James Hudson, 3 Carl Hayman (c), 2 Rob Vickers, 1 Jon Golding.
Replacements: 16 Alex Walker 17 Micky Ward 18 Laurence Ovens 19 Josh Afu 20 Ed Williamson 21 Hall Charlton 22 Rob Miller 23 Gcobani Bobo.
Northampton: 15 Ben Foden, 14 Chris Ashton, 13 Jon Clarke, 12 James Downey, 11 Bruce Reihana, 10 Shane Geraghty, 9 Lee Dickson, 8 Roger Wilson, 7 Neil Best, 6 Phil Dowson, 5 Juandre Kruger, 4 Courtney Lawes, 3 Santiago Bonorino, 2 Dylan Hartley (capt), 1 Soane Tonga'uiha.
Replacements: 16 Brett Sharman, 17 Regardt Dreyer, 18 Euan Murray, 19 Christian Day, 20 Scott Gray, 21 Alan Dickens, 22 Stephen Myler, 23 Joe Ansbro.
Referee: Greg Garner