England scrum-half Alex Mitchell's try helped Northampton secure an 18-12 win over Saracens at the StoneX Stadium.

Ollie Sleightholme crossed for the first try after 52 minutes, but Tom Parton quickly cut the gap to 13-5.

Mitchell's try took Saints 13 points clear and they held out under huge pressure, despite Alex Lewington's try.

Defeat for the top two, following Sale's defeat by Quins on Friday, further squeezed together the top half of the table - with the top six now separated by a mere four points.

A fifth win in six for Saints moves them within two points of leaders Sale in fifth, while Sarries - who had won their previous five and scored 127 points in their previous three matches - slip to fourth.

Owen Farrell missed the match for Sarries with a knock, having ruled himself this week out of the Six Nations for mental health reasons,.

Mitchell produced a superb second-half try which ultimately proved the match-winner.

It was a handy response to the virtuoso performance of Harlequins' Marcus Smith - who Mitchell may line-up alongside in the half-back positions for England - which put the skids under Sale.

With defending Premiership champions Saracens unable to impose themselves, Smith broke the deadlock in the 18th minute after Saints forced their way into the home 22 - where the hosts went off their feet.

In a tight first half, where the ball spent more than its fair share of time heading skywards, Fin Smith then booted Northampton 6-0 ahead after Ethan Waller won a scrum penalty.

Sarries responded with their first concerted spell of pressure, sending two penalties to the corner, but the Saints defence - disciplined throughout the first 40 - refused to budge an inch.

Northampton looked to have wasted a huge opportunity for the first try when they spurned a three-on-one from George Furbank's break but, from the very next phase, Fraser Dingwall executed a perfect crossfield kick for Sleightholme to dot down.

An angry Saracens soon responded, Maro Itoje twice going close against a besieged Saints defence before Manu Vunipola's long throw out to the left allowed the unmarked Parton to cross.

Sarries began to squeeze as mistakes began creeping into the tiring Saints game, but Northampton served up the decisive score, Mitchell finishing off a two-on-one following Angus Scott-Young's break.

The two-score cushion lasted just six minutes as Alex Goode's nicely weighted grubber kick put Lewington in the corner, and a clutch conversion from Farrell's replacement Manu Vunipola brought the Sarries to within six points.

Northampton had six long minutes to survive but summoned up their earlier defensive heroics to earn their first Premiership win at the StoneX since 2019.

Saracens director of rugby Mark McCall:

"We were second best in all areas, to be honest. We wanted consistency in our performance but we were way off it today, especially in the first half.

"Physically, both sides of the ball, we weren't great, and in general our movement off the ball was poor as well.

"We got a little bit better in the last 20 minutes of the match, when everything was on the line, and that's the kind of energy we need from the start of the match, to be honest.

"Northampton were fantastic and they thoroughly deserved to win."

Northampton Saints director of rugby Phil Dowson:

"We talked during the week about the quality of Saracens being a measuring stick for some of the things we worked on from last season in terms of our defence, our set-piece and elements of that.

"We talked before the game about discipline issues and we want to be hard at the breakdown and create turnovers.

"That comes with an element of risk, but we ran that balance pretty well in this game, in terms of we got turnovers and didn't give many penalties away.

"The decision-making of when to be more pragmatic is the key for us. It's an exciting season and it adds pressure every week."

Saracens: West; Dan, Clarey, Itoje (capt), McFarland; Gonzalez, Christie; Vunipola, van Zyl, Vunipola, Parton, Tompkins, Cinti, Maitland, Goode.

Replacements: George, Vunipola, Judge, Tizard, Knight, Davies, Hartley, Lewington.

Northampton: Furbank (capt); Seabrook, Freeman, Dingwall, Sleightholme; Smith, James; Waller, Matavesi, Davison, Munga, Coles, Lawes, Pearson, Graham.

Replacements: Langdon, Waller, Mills, Mayanavanua, Scott-Young, Mitchell, Litchfield, Hendy.

Referee: Christophe Ridley.

CLARIFICATION: In an earlier version of this article, Alex Mitchell was mistakenly referred to as a fly-half who could target Owen Farrell's vacant England position.