In atrocious conditions at kick-off, it did not take long for Leicester to go in front, as Josh Manz went over in the first minute.
Newcastle responded with two scores of their own 10 minutes later through Micky Rewcastle and Tom Cardell, only for Hanro Liebenberg to restore the hosts’ advantage.
Will Wand extended the Tigers’ lead in the second half, before the sides traded tries again – Harrison Obatoyinbo briefly reducing the deficit before Izaia Parese put Leicester up by nine once more.
The home side were perfect from conversions, three coming from the boot of James O’Connor and one from Tom Whiteley. Ethan Grayson, meanwhile, added four points to the visitors’ tally.
Leicester’s gap at the top of Pool B stretches to eight points, while Newcastle remain five points behind second-placed Saracens after a 13th defeat in 19 games in 2025-26.