Shane Geraghty rescued a draw for LV= Cup holders Northampton with a last-minute try in a tight battle at Vicarage Road.
New signing Gavin Henson was introduced to the crowd at half-time, but the Wales centre will not be available to play until he finishes his involvement with the television programme Strictly Come Dancing.
Saracens gave a debut to 18-year-old full-back Ben Ransom but lost fly-half Alex Goode shortly before kick-off with a sore quad. Nils Mordt took his place while Northampton started England's Geraghty at number 10.
It was Geraghty who made his mark first, steering over a fourth-minute penalty awarded for offside by referee Chris White from in front of the posts.
With Goode absent, scrum-half Richard Wigglesworth took over kicking duties for the hosts, and the England international made no mistake after six minutes, another penalty awarded for offside.
The game developed into a tight slog, punctuated by White's whistle, and it was Saracens who got their noses in front after 17 minutes.
Wigglesworth seemed ambitious when shaping to attempt a shot at goal from halfway. But his shot was still climbing as it bisected the posts.
Geraghty was handed an opportunity to equalise two minutes later, but this time his shot was shanked wide.
Saracens then found touch deep in enemy territory, and when the lineout went long, Mark Easter caught the ball but was pounced upon immediately and driven backwards over his goal-line. However White found something to blow for, ending the attack.
The home side were gradually nudging Northampton onto the back foot, but it was difficult for either side to build momentum, so often were they halted by the referee.
The visitors took the lead after 28 minutes when loosehead prop Regardt Dreyer was driven over to the right of the posts, and Geraghty added the conversion.
In their next attack, Saracens were awarded another penalty, this time for a ruck offence, and Wigglesworth completed his hat-trick of successful kicks.
And when England wing David Strettle made a searing break at the heart of the defence, White decided he was halted illegally and Wigglesworth made it four from four.
Northampton hit back in style after 37 minutes when Geraghty's clever inside pass foxed the defence and left wing Paul Diggin dashed through the gap. Geraghty's conversion was spot-on.
The half ended as it began, with penalties. Wigglesworth's first attempt from wide on the right flew the wrong side of the near post. And when hooker Brett Sharman was sin-binned for a ruck offence, the task looked easier. But Wigglesworth, so deadly earlier, missed again.
Wigglesworth was presented with another chance 30 seconds after the restart, but his shot, from close to half-way, faded to the right.
Despite being a man short, Northampton took the game to Saracens who were forced ever deeper and to defend in numbers.
But after fine approach work, Geraghty wasted a strong position by attempting a drop-goal that flew way off target.
It acted like a release valve because Saracens swept upfield and laid siege, switching play from left to right and back before Justin Melck smashed his way over by the left of the posts after 51 minutes, and Wigglesworth got back on track with the conversion.
Referee White was unfailingly consistent, and both teams knew to expect no mercy if they transgressed.
The home side increased their lead after 64 minutes when Wigglesworth scored his fifth penalty after Northampton strayed offside in front of their posts.
Northampton had the chance to hit back immediately, but Geraghty's penalty shot crashed back off the right-hand post and into the arms of lock Hayden Smith, who happily hoofed it clear of his 22.
Saracens launched two very promising attacks, but both broke down on sloppy individual mistakes, a fluffed pass by Kameli Ratuvou and an intercepted pass from Adam Powell.
Geraghty, who opened the scoring, then darted in off a penalty scrum to equalise in the last minute, although his conversion flew wide.