Saracens inflicted a fifth successive Gallagher Premiership defeat on Bristol but were forced to dig deep for their 39-31 victory at StoneX Stadium.
At one point it looked as though the champions would be punished for Owen Farrell's wayward kicking after the England captain failed to convert his side's first three tries and a penalty.
Farrell's inability to land the points contrasted with Callum Sheedy's pinpoint accuracy from the tee and the difference between the fly-halves' success rate was magnified until Jamie George crossed in the 54th minute.
Tom Willis then went over and George added a second late on to ease the tension created by Bristol's refusal to roll over in their pursuit of a first-ever victory in north London.
Once again Maro Itoje was at the heart of Saracens' resistance as the England second row continued his resurgence in form with a blockbuster display that was recognised with the man of the match award.
The afternoon's most effective scoring weapon was the maul and at this Mark McCall's men excelled, using it as the platform to claim their opening try with Farrell wrestling his way over from close range.
Bristol had started full of intent but by the 12th minute they had conceded a second try as Alex Lewington rounded off an accurate passage of play full of hard lines and sharp handling.
By building pressure through keeping the ball alive the Bears hit back when unmarked lock Joe Batley rounded off a lively attack by going on the charge before touching down with an outstretched arm.
Saracens returned to their maul for their response with Billy Vunipola dummying and slipping over but Bristol continued to show their teeth, with Max Malins growing more influential against his former club.
It became the visitors' turn to cross through a line-out maul finished by Ellis Genge and when they added a second through the power of their pack - Gabriel Oghre went over this time - they had snatched the lead.
Due to Farrell's wayward kicking Saracens trailed 21-15 entering the break and his troubles continued into the second half when he sent a long-range penalty wide.
He delivered a pinpoint cross-field kick for Lewington to touch down again, however, and this time the conversion went over via a bounce off the left post.
Sheedy slotted a penalty but Saracens built up a head of steam and after successive line-outs in the left corner they struck through George.
Bristol's play became panicky and they were breached with 12 minutes left when Theo McFarland's strong run was continued by Gareth Simpson until the strength of Willis finished the move.
But they refused to roll over and when Kieran Marmion rounded off a deadly break by Gabriel Ibitoye the game was blow wide open once again.
Saracens dominated the closing stages, however, and were rewarded with George's second try which swept them out of reach.
*copy from PA.
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