Vereniki Goneva blew away Newcastle with a 17-minute hat-trick as the Tigers got their Premiership campaign off to a flying start with a bonus-point win.
Goneva, a target for French side Castres late last season, decided to stay at Welford Road and he repaid the club with tries in the 44th, 50th and 61st minutes.
Leicester, who delayed England flanker Tom Croft's return from a knee reconstruction after he pulled up in training, edged a poor first half in which debutant Freddie Burns kicked four penalties.
Newcastle fielded 10 new signings, the stand-out being Italy lock Josh Furno. Former Leicester favourite Alesana Tuilagi made a brief appearance early on as a blood replacement.
The match exploded into life 30 seconds after the restart when Sinoti put Simon Hammersley through a gap and Falcons flanker Richard Mayhew dotted down.
Manu Tuilagi's barnstorming run created Goneva's first try three minutes later, and the Fijian scored again after great work by Burns after a ruck near the posts.
The Falcons shot themselves in the foot to hand Goneva his treble on a plate. Replacement scrum-half Ruki Tipuna's pass on the Leicester line was intercepted by Goneva, who outpaced the chasers and ran 95 metres for a try that Burns converted to make it 31-10.
Five minutes later it was 36-10 after David Mele, on for Ben Youngs, scored a pushover try.
Andy Saull scored Newcastle's second try nine minutes from time after a rolling maul. It was scant consolation.Reuse content