Alex Lozowski scored 20 points as Saracens earned a hard-fought win over Northampton at Franklin's Gardens.
At the interval, the sides were locked 6-6 as Dan Biggar and Lozowski traded penalties. Biggar twice cancelled out Lozowski penalties in an attritional and even first half, played in wet, slippery conditions.
Northampton had put Saracens under pressure in the first half but were unable to penetrate Sarries defence.
Alex Goode glided through a small opening and fed Lozowski who slid in for the game's first try just four minutes after the restart. He added a conversion and a further penalty to extend the lead to 16-6 after an hour.
Woolstencroft was driven over for the second try just a minute after prop Conor Carey was yellow-carded for collapsing a maul.
Maro Itoje rubbed salt in the Northampton wounds after he scored following Eroni Mawi's breaking from a maul. Lozowski converted to score his 20th point of the game (1 try, 3 penalties and 3 conversions).
Tom Woolstencroft sealed victory with a pushover try before Maro Itoje crossed late on as a tiring Saints side wilted – ending the game with 13 men following injuries.
Saracens matched the win of runaway leaders Leicester and remain second, but slipped back to nine points adrift as the Tigers secured a bonus point in beating Newcastle.
Northampton went into the match on a run of three straight defeats in all competitions – and seven in their past nine – but had only lost once at Franklin's Gardens this season.
Northampton: Furbank; Sleightholme, Hutchinson, Francis, Skosan; Biggar, Mitchell; Waller, Matavesi, Hill, Coles, Ratuniyarawa, Lawes, Ludlam (capt), Augustus.
Replacements: Fish, Iyogun, Carey, Ribbans, Wood, James, Dingwall, Tuala.
Sin-bin: Connor Carey (71)
Saracens: Malins; Maitland, Lozowski, Tompkins, Daly; Goode, van Zyl; M Vunipola, George (capt), Beaton, Itoje, Isiekwe, McFarland, Earl, B Vunipola.
Replacements: Woolstencroft, Mawi, Milasinovich, Hunter-Hill, Wray, de Haas, Manu Vunipola, Segun.
