Darren Cave and Robbie Diack crossed for Ulster tries in the RaboDirect Pro12 tussle at Stadio Monigo but Ulster struggled to build on those, and four penalties from Treviso fly-half Mat Berquist made it closer than it needed to be come the closing stages.
The visitors brought impressive form to Italy, having been beaten just once in 10 outings. Against a Treviso side on a five-game losing run, it was hard to see Ulster being pushed close, but they very nearly went down to defeat, having to stave off late pressure as the Italians sought a winning score.
Berquist booted Treviso ahead early on, but once Ulster got their noses in front in the 11th minute, with Cave dashing over and Ruan Pienaar converting, the Irish team were never headed again.
Ulster were careless enough to let Treviso stay in touch though, giving away a penalty early in the second half that Berquist booted to narrow the gap to 7-6. Diack burrowed over for Ulster’s second try in the 51st minute, and again Pienaar added the extras.
What should have then been a formality for Ulster became anything but as Berquist sliced into the lead with a pair of penalties, making for the tense finale that Ulster just about survived.
Benetton Treviso scorers: Pens: Berquist 4.
BENETTON TREVISO: Williams, Nitoglia, Sgarbi, Bacchin, Pratichetti, Berquist, Semenzato, Muccignat, Sbaraglini, Fernandez-Rouyet, Pavanello, Bernabo, Vosawai, Swanepoel, Filippucci.
Replacements: Ceccato for Pratichetti (65), Di Bernardo for Semenzato (57), Lucchese for Sbaraglini (65), Acosta for Fernandez-Rouyet (73), van Zyl for Bernabo (50), Lubian for Vosawai (73).
Ulster scorers: Tries: Cave, Diack. Cons: Pienaar 2.
ULSTER: Payne, Gilroy, Cave, L. Marshall, Allen, Pienaar, P. Marshall, Court, Herring, Lutton, Muller, Stevenson, Diack, Doyle, Wilson.
Replacements: Scholes for Allen (52), Black for Court (41). Not Used: Annett, Macklin, McComb, McComish, Heaney, R. Andrew.
Ref: George Clancy (Ireland).