An increasingly assured performance after a slow start meant Saracens moved up to fourth place in the table, their highest position under their new director of rugby Alan Gaffney while their domination of the physical exchanges in the second half bodes well for the New Year.

Their hosts' ill-discipline kept the Saints in the game for the first 40 minutes but that problem was rectified at halt-time, after which the home side dominated in every area. Northampton were kept scoreless and the Sarries fly-half Glen Jackson made hay to net 23 points including a try, three conversions out of a possible four and and four penalties.

It had taken the home side until after half-time to get two scores clear of the visitors when the first sustained spell of Saracens pressure, inspired by Dan Scarbrough and Ben Skirving, resulted in David Seymour going close on the right before the ball was recycled to his right.

After one phase the ball fell to Jackson who dummied between two Northampton defenders from a couple of yards out to score beneath the posts, with the conversion a formality for the Premiership's most accurate marksman.

As Saracens gained the upper hand physically, Northampton's error count increased, with Saints coughing up the ball at the breakdown and by the hour Jackson had landed his fourth penalty of the evening. The home side then rammed home their dominance up front, sealing the match with a penalty try with eight minutes remaining as the Northampton front row were put to the sword.

The bonus point came when new signing Census Johnston bundled over in the final minutes on his debut. Jackson missed the conversion, which was about the only false note he struck all evening with the rout completed when the Northampton centre Robbie Kydd was sent to the sin-bin in added time for a high tackle.

As an illustration of the shortcomings of the Premiership, the first half had been sadly exemplary. The 40 minutes boiled down to a kicking match between two New Zealand fly-halves with only flashes of skill in a miasma of poor handling and ill discipline at the breakdown.

The ball was produced from the tackle area with the urgency of a traffic queue leaving a shopping centre on the opening day of the sales, and of the few flashes of inspiration the best chances involved Saracens' Tongan and Fijian wings Tevita Vaikona and Kameli Ratuvou.

Vaikona was unlucky to be bundled into touch in the 10th minute just a couple of metres from the Northampton try-line, while Ratuvou was the beneficiary of a pass from Kevin Sorrell after Shane Byrne had snaffled a loose Northampton throw at a line-out just outside the visitorsí 22.

The rapid Fijian's try approaching the half-hour was the highpoint of the opening exchanges in which Saracens infringed enough to keep Northampton in the match with Spencer putting over five penalties. That, however, was as good as it got for the Saints.

Saracens Scarbrough; Vaikona, Sorrell, Powell, Ratuvou; Jackson, De Kock; Lloyd, Byrne, Visagie, Chesney, Raiwalui (capt), Gustard, Seymour, Skirving.

Tries: Ratuvou, Jackson, penalty, C Johnston. Cons: Jackson 3. Pens: Jackson 4.

Replacements Russell for Seymour 72; C Johnston for Visagie 72, Penney for Vaikona 74, Taylor for Jackson 80

Northampton Going; Lamont, Mallon, Kydd, Bourret; Spencer, Vass; Smith, Thompson, Barnard, Damien Browne, Lord, Easter, Harding, Daniel Browne.

Replacements Budgen for Barnard 61; Tupai for Daniel Browne 62; Diggin for Going 62; Hartley for Thompson 66, Tonga'uiha for Smith 66; Howard for Spencer 72

yellow card: Kydd, 80

Referee D Pearson (Northumberland). Attendance 12082