Ulster, more or less free to concentrate on the Pro12 with little hope of advancing in the Champions Cup over the next two weeks, almost put a serious dent in their league hopes.
They were cruising when they opened up a 24-0 lead after just 25 minutes but in the end were left hanging on as Treviso rallied and almost snatched it at the death when centre Michele Campagnaro intercepted but dropped the ball with a clear run to the line from halfway.
It would have been rough justice on Paddy Jackson who was the main instigator of Ulster’s whirlwind start.
Jackson controlled the game from out-half in the opening 40 minutes and got in for the opening try.
Ulster showed their intentions from the outset, going for the corner with a penalty in front of the posts and two minutes later the pressure paid off when Jackson chased his own grubber to score his first try of the season.
He added the conversion and a penalty for a 10-0 lead after 18 minutes despite having Craig Gilroy binned for an infringement when it seemed Treviso were poised to score in the corner.
A strong counter-attack by Ulster saw Gilroy mark his return to action by slipping the final pass for Ruan Pienaar to canter over.
A wonderful inside pass from Jackson sent Tommy Bowe, who passed a late fitness test on a thigh problem, over for his 59th league try as Jackson converted to make it 24-0 after just 25 minutes.
But that was as good as it got for Ulster.
Sam Christie pulled back a try for Treviso and his New Zealand compatriot Jayden Hayward converted to make it 24-7 at the break.
Treviso grew in confidence and were rewarded when Italian flanker Francesco Minto scored after a good drive. Hayward continued his splendid kicking to convert and then haul back the deficit to just four points. But Ulster held out in a nervous finish.
“Away games are all tough and we got that foundation to kick on and unfortunately we didn’t do it. But I am delighted to get the four points,” said Ulster coach Neil Doak.
“There is an outside chance of us qualifying for Europe but we have got to be sensible with regards to the players. We have got a long list of injuries – we have overplayed a few guys.
“We will just have to take stock and try and pick the best side that we can next week,” added Doak.
Scorers for Treviso: Tries: S Christie, F Minto; Conversions: J Hayward (2); Penalties: J Hayward (2).
Scorers for Ulster: Tries: P Jackson, R Pienaar, T Bowe; Conversions: P Jackson (3); Penalty: P Jackson.
TREVISO: J Hayward; A Esposito, M Campagnaro, L Morisi, A Pratichetti; S Christie, E Gori; M Zanusso, D Giazzon, R Harden; T Vallejos, C Van Zyl; M Barbini, A Zanni (capt), D Budd.
Replacements: F Minto for M Barbini (1-14), A Anae for D Giazzon, F Minto for M Barbini and M Fuser for T Vallejos (46), D Rae for M Zanusso (57), A Lucchese for E Gori, J Ambrosini for L Morisi (both 71), M Swanepoel for Van Zyl (73).
ULSTER: L Ludik; T Bowe, D Cave, S Olding, C Gilroy; P Jackson, R Pienaar; C Black, R Best, W Herbst; A O’Connor, D Tuohy; R Diack, C Ross, R Wilson.
Replacements: B Ross for W Herbst (41), J Payne for D Cave (51), L Stevenson for A O’Connor (60), S Reidy for C Ross (61).
Referee: Ben Whitehouse (WRU).