Leicester (14) 47
Tries: Hipkiss 2, Woods, Flood, Hamilton 2, Mauger Cons: Flood 5, Vesty
Viadana (3) 8
Try: Canavosio Pen: Law
Hamilton scored a quick-fire brace at the end of the first half for Leicester
Leicester kept their Heineken Cup hopes alive with a bonus-point victory over Viadana to go top of Pool Three.
Tries from Dan Hipkiss, Ben Woods, Toby Flood and Scott Hamilton, with a brace, gave Leicester a 35-3 half-time lead, Flood converting all five.
Pablo Canavosio went over for the visitors before Hipkiss and Aaron Mauger added further Tigers tries.
Later on Saturday Ospreys lost 27-7 at Clermont Auvergne, who join them on 16 points, one point behind the Tigers.
Leicester's last pool game is away to Ospreys next Saturday 23 January, with Clermont visiting Viadana at the same time.
The Tigers suffered a blow when England flanker Tom Croft was carried off the field after 27 minutes after once again injuring his left knee.
He had just returned from a six-week lay-off after injuring the knee earlier in the season and is expected to be out for a further five weeks having damaged his medial ligament, which seriously hinders his Six Nations chances.
By the time Croft went off the Tigers already had two tries on the board, through Hipkiss and Woods.
Flood dummied his way over five minutes after Croft's exit and two minutes later Hamilton snaffled a loose ball to claim what might prove to be a vital bonus point come the final weekend.
Hamilton completed his brace just before the interval but Leicester lost their way after the break, with some clumsy passing hindering their attempts to add to their try tally.
They finally added a sixth try 10 minutes from the final whistle before a typically thunderous Alesana Tuilagi charge sent Mauger over with a clever pass five minutes later.
Leicester boss Richard Cockerill:
"This game was difficult because only one team wanted to play rugby. Viadana came to stop us playing, which was frustrating, but we played well in the first half, scoring five tries.
"The second half was pretty dire. I sent some boys on to freshen things up, and we scored two good tries at the end, but every breakdown was a bun fight.
"I can't really blame them, coming to play the top team in the Guinness Premiership. I would probably have done the same thing in their shoes.
"Now it's time to move on. We scored seven tries, took the maximum points from the tie and we start planning for Ospreys immediately. We must win there if we are to win our group."
Cockerill on the injured Croft:
"It's a blow for the lad to injure the same knee, and while England manager Martin Johnson might be concerned about Tom's Six Nations situation, my only concern is that we won't have him in Swansea next weekend.
"I have my job to do, Martin has his. But Crofty is a world class player who hadn't seen action for ages. He needed playing time, so I had no qualms starting him."
Leicester: Hamilton; Tuilagi, Hipkiss, Vesty, Tuqiri; Flood, B Youngs; Ayerza, Chuter, Cole, L Deacon, Parling, Croft, Woods, Crane.
Replacements: J Murphy for Hamilton (58), Mauger for Flood (52), Grindal for B. Youngs (52), Stankovich for Ayerza (67), White for Cole (52), Moody for Parling (58), Newby for Croft (26).
Not Used: Davies.
Viadana: Law; Pratichetti, Cox, Johansson, Sepe; Hola, Canavosio; Sciamanna, Ferraro, Garcia, Del Fava, Hohneck, Persico, Benatti, Erasmus.
Replacements: Pace for Sepe (42), Wilson for Canavosio (62), Cagna for Sciamanna (62), Santamaria for Ferraro (66), Milani for Garcia (70), Krause for Del Fava (50), Birchall for Benatti (51).
Not Used: Furno.
Sin Bin: Law (48).
Ref: James Jones (WRFU).