|Newcastle (3) 17|
|Tries: Ah You, Takulua Cons: Takulua 2 Pen: Takulua|
|Northampton (24) 31|
|Tries: Collins 3, Mitchell Cons: Biggar 4 Pen: Biggar|
Newcastle Falcons' relegation fears deepened as Northampton Saints held off a second-half revival from the hosts to go fourth in the Premiership.
Three first-half tries from an inspired Tom Collins gave play-off hopefuls Saints a 24-3 lead at half-time.
Newcastle hit back after the break through Rodney Ah You and Tane Takulua.
But Alex Mitchell went over late on to seal the win for Saints and leave the Falcons seven points adrift at the bottom with just two games to go.
The defeat means Newcastle could be relegated by the end of the weekend, if results go against them, ending their six-year stay in the top tier.
It also guaranteed survival for last season's promoted side, Bristol Bears, who now cannot be caught by Dean Richards' men.
A victory for 10th-placed Leicester Tigers on Saturday at home to Bristol, coupled with a win for 11th-placed Worcester at home to Gloucester on Sunday, would send the Falcons down.
And even if those results go their way, Newcastle, who were semi-finalists last season, must then beat both Gloucester (4 May) and Bristol (18 May) to have any hope of survival.
But for Saints, who are now one point above fifth-placed Harlequins, their resilient performance galvanised their ambitions of competing in next month's play-offs.
Newcastle director of rugby Dean Richards:
"We lacked intensity and we lacked accuracy in the first half. We came back in the second half and then we tried a little bit too hard at the end which gave them that try to finish us off.
"Mathematically, we've still got a chance, but we've now got to go down to Gloucester and get five points there and then get five points against Bristol here.
"It is what it is and if Worcester win on Sunday and Leicester win tomorrow then it's good night us.
"People wrote us off six games ago and had we won against Leicester and Northampton, we wouldn't be sitting here talking about relegation, we would probably have been talking about something else."
Northampton boss Chris Boyd:
"We're delighted we had three tries in the bag before half-time, and we're delighted to come here and get five points.
"The way they were defending and the way we were holding through the middle, we knew we were going to get some chances on the outside, and Tom Collins has pretty tricky feet and he's pretty quick.
"In the second half they defended further up and that space disappeared, and it also disappeared because we weren't getting any front-foot ball and they were much more aggressive at the breakdown.
"We've got Worcester next week, which is our last game at home, and we'd like to finish the the season positively at Franklin's Gardens."
Newcastle: Hammersley, Goneva, Harris, Matavesi, Sinoti, Flood, Takulua, Mulipola, McGuigan, Ah You, Green, Davidson, Chick, Wilson, Nagusa.
Replacements: Cooper, Lockwood, Davison, Robinson, Graham, Young, Swiel, Williams.
Northampton: Tuala, Collins, Hutchinson, Burrell, Naiyaravoro, Biggar, Reinach, van Wyk, Marshall, Hill, Ratuniyarawa, Lawes, Gibson, Wood, Harrison.
Replacements: Ma'asi, Waller, Franks, Coles, Onojaife, Mitchell, Grayson, Kellaway.
For the latest rugby union news follow @bbcrugbyunion on Twitter.