Leicester moved clear of Ospreys in Heineken Cup Pool Two after a bonus-point win over Treviso at Welford Road.
A penalty try got the Tigers on the scoreboard and Manu Tuilagi and Julian Salvi (2) crossed before the break.
Dean Budd and Lorenzo Cittadini hit back before a Matt Smith try clinched a bonus point for the hosts.
Christian Loamanu touched down late on but Leicester held on for a win that leaves them very much in the hunt for a quarter-final place.
However, the manner in which Leicester faded in the second half does not auger well for them ahead of Saturday's return fixture at Stadio Communale di Monigo.
If the group goes to form and pedigree, four-time European champions Toulouse's Welford Road visit next month is likely to decide whether they or the Tigers progress as pool winners.
Leicester: Tait, Hamilton, Tuilagi, Bowden, Goneva, Ford, B. Youngs, Ayerza, T. Youngs, Castrogiovanni, Kitchener, Parling, Slater, Salvi, Waldrom.
Replacements: Smith for Goneva (41), Young for B. Youngs (66), Mulipola for Ayerza (61), Hawkins for T. Youngs (41), Crane for Parling (61), Thorpe for Salvi (60).
Not Used: Cole, Murphy.
Benetton Treviso: McLean, Loamanu, Benvenuti, Morisi, Pratichetti, Ambrosini, Gori, Rouyet, Sbaraglini, B. Roux, Pavanello, Bernabo, Favaro, Budd, Vosawai.
Replacements: Semenzato for Morisi (64), Rizzo for Rouyet (40), Ghiraldini for Sbaraglini (40), Cittadini for B. Roux (40), Minto for Pavanello (40), Derbyshire for Vosawai (64).
Not Used: C. van Zyl, Di Bernardo.
Sin Bin: Favaro (54).
Ref: Pascal Gauzere (France).