Pat Lam’s men were hoping to register their third away win in Pool 3 and keep alive their hopes of a European quarter-final berth, but the powerful Aviva Premiership leaders were in no mood to slip up.
Chris Ashton’s sixth try of the pool stages combined with efforts from David Strettle and Schalk Brits ensured an 18-6 interval lead for Sarries.
Brits scored in first half injury-time while Connacht prop Nathan White was in the sin-bin. The westerners had been ahead earlier thanks to two Dan Parks penalties.
Strettle was set free for the bonus point score barely a minute into the second period and further tries from Alex Goode and George Kruis widened the gap to 29 points.
The tiring Connacht defence gave way as replacements Chris Wyles, Jackson Wray and James Johnston all crossed the whitewash in the final quarter.
There was still time for Strettle to complete his hat-trick and fellow winger Ashton dived over in injury-time for his second, as Mark McCall’s side had a comfortable passage through to the last-eight.
The returning Gavin Duffy broke into space early on as Connacht settled quickly to their task, and a long range penalty from Parks gave the visitors a sixth minute lead.
Saracens’ well-set scrum forced a penalty in response, but Charlie Hodgson watched his kick slide just to the right of the posts.
The Sarries number 10 was quickly back in the thick of the action, finding Brad Barritt and Mako Vunipola with inviting short passes. The latter surged into the Connacht 22 and Ashton evaded the grasp of Matt Healy and Duffy to touch down in the right corner.
The try went unconverted and Connacht’s defensive workload was beginning to increase, apart from a near miss when Robbie Henshaw shot up to almost gather an intercept.
Parks’ reliable right boot briefly sent Connacht back in front by the 20th minute, punishing Brits for a ruck infringement, before Hodgson answered back from the kicking tee.
Sarries soon had their second try on the board. Full-back Goode countered from a quickly-taken lineout, slipping by three defenders before swift deliveries from Brits and Duncan Taylor opened the way for Strettle to score on the left.
Connacht failed to take advantage of a scrum in the hosts’ 22 and they struggled to get over the gain-line with regularity, but two positive scrums got the westerners on the move.
However, matters worsened for Lam’s side when White was sin-binned for stamping on Barritt at a midfield ruck - replays showed his boot made contact with the centre’s face and he was very fortunate to avoid a red card.
White’s front row colleague Sean Henry also went off injured and although evasive running from wingers Healy and Fionn Carr showed a glimpse of Connacht’s attacking talent, Sarries were now dominant.
They rounded off the first half with a try from hooker Brits from a well-controlled maul drive, with Hodgson’s conversion attempt from the right coming back off the post.
Just 71 seconds after the restart, Saracens secured their bonus point and again it came from a Goode-inspired move. He spotted a mismatch, ghosting between Denis Buckley and Eoin Griffin, and found Taylor who fed Strettle for a simple run-in on the left.
Goode stamped his mark on the game even further when Connacht were slow to chase a Kieran Marmion kick. Goode gathered it just inside the visitors’ half and his pace took him past Michael Swift and Jason Harris-Wright and all the way to the try-line.
There was little respite for the westerners, but they fought on valiantly and Healy did well to prevent Ernst Joubert from touching down in the right corner.
They could not hold out though, Sarries pressing from two close-in scrums before lock Kruis was driven over for try number five. Hodgson managed to add the extras on this occasion.
Saracens replacement Alistair Hargreaves was lucky not to see yellow for a foot trip on Carr, but the tries continued to come for McCall’s charges with Jamie George’s one-handed pass sending fellow replacement Wyles over to the left of the posts.
Turnover ball set up Wray for a fine finish following smart play again from Hodgson and Goode, and prop Johnston crashed over on the end of a lineout maul.
Despite the best efforts of spirited scrum half Marmion and Rodney Ah You and Michael Kearney, who were both prominent as replacements, Connacht were contained in their own half for the most part and late efforts from Strettle - collecting his own chip kick - and Ashton completed the rout.