Jamie George celebrates his try at Welford Road with Saracens full-back Alex Goode
Champions Saracens ran in six tries as they inflicted Leicester's heaviest-ever Premiership defeat.
Charlie Hodgson kicked three penalties and converted his own try as Saracens raced into a 16-3 lead.
Ernst Joubert and Niall Morris traded tries before the break but Sarries moved out of sight with further scores from Owen Farrell and Jamie George.
Julian Salvi pulled one back but Brad Barritt and Joubert's second made Ben Woods' late score mere consolation.
Last season's runners-up Leicester, whose previous heaviest Premiership defeat was 45-17 against Wasps in 1998, have now lost three of their opening four games, although their cause has not been helped by having 12 players on World Cup duty and a raft of injuries.
Saracens have eight players at the World Cup themselves but eased into a 9-3 lead as Hodgson kicked three penalties to Billy Twelvetrees' one.
Hodgson then converted his own nicely-worked try, before Joubert capitalised on some poor defending to power over for Sarries' second try.
Winger Morris went over to ensure Leicester went in at the break only 23-11 down but quickfire tries from Farrell and George at the start of the second half put the result beyond doubt.
Salvi did cross following good work from Matthew Tait, but Joubert's second and Barritt's score under the posts edged Saracens towards the 50-point mark.
Woods grabbed a consolation try for the Tigers with only minutes left, but Farrell landed a penalty with the last kick of the game to ensure Saracens headed home with a half-century of points to their name.
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