Ulster were pushed off the top of the Pro12 table as Treviso fought back to force a draw at Ravenhill.
The home side looked in control as tries from Andrew Trimble and Stuart Olding helped them lead 17-3.
However, a hat-trick of tries by New Zealander Dean Budd and a Robert Barbieri touchdown helped Treviso snatch a draw which they deserved.
Glasgow's win over Cardiff moves them level with Ulster but the Warriors have a superior score difference.
It could have been even worse for the home side as impressive Treviso fly-half Alberto Di Bernardo had a chance to snatch victory with his last-gasp conversion attempt but he was inches wide with the difficult kick from near the touchline.
Ulster fly-half Paddy Jackson was given the kicking duties after his struggles for Ireland at Murrayfield last weekend and he responded impressively by slotting seven out of nine attempts as he racked up 19 points.
But they were plenty of negatives for Ulster coach Mark Anscombe to mull over after his side had squandered a 14-point advantage with the sin-binnings of Iain Henderson and Lewis Stevenson helping Treviso to get back into the game.
With Ulster already beset by injuries, the sight of Ruan Pienaar hobbling off near the end with a suspected ankle strain will also be a concern for Anscombe.
Di Bernardo opened the scoring with a third-minute penalty which Jackson failed to match as he was badly off target from 35 metres.
However, Jackson regrouped to have an accomplished night with the boot both with his goal-kicking and attempts to find touch.
Trimble burst through the Treviso defence to score Ulster's first try in the 18th minute after Henderson had soared to win a line-out and delivered quick ball to Pienaar.
Jackson stroked over the conversion and his penalty 10 minutes later extended Ulster's lead to 10-3.
Ulster profited from the sin-binning of Treviso replacement Tommaso Iannone to notch their second try as lively young centre Olding ran 40 metres past two tackles to score under the posts, with Jackson adding the conversion.
At that stage, Ulster looked to have subdued the visitors but Henderson's 36th-minute sin-binning gave the Italians a lifeline which they exploited on the stroke of half-time as Budd ran in a try at the corner flag after an initial break by superb full-back Brendan Williams.
Di Bernardo slotted the tough conversion to leave only a score between the teams at the break.
Jackson extended Ulster's lead after the break but lock Stevenson's sin-binning for his second high tackle of the night was punished as Treviso mauled in another try with Barbieri supplying the finish and Di Bernardo adding the conversion.
Another Jackson penalty left Ulster 23-17 ahead but Treviso were starting to dominate possession and they were soon ahead after Budd scored his second try in the 64th minute following his own charging down of Ricky Andrew's attempted clearance.
Di Bernardo's conversion put Treviso ahead for the first time since the opening minutes.
Ulster looked to have finally subdued the Italians as Jackson penalties in the 69th and 78th minute put five points between the teams.
But Ulster wing Michael Allen failed to retain possession from the restart and in the final play of the game, Budd completed his hat-trick as Treviso had numbers out wide.
Di Bernardo had slotted an equally difficult conversion in first-half injury but he was inches wide with the last kick of the game as the match ended level.
Ulster: R Andrew, A Trimble, D Cave, S Olding, M Allen, P Jackson, R Pienaar; J Afoa, R Herring, D Fitzpatrick, L Stevenson, D Tuohy, I Henderson, M McComish, R Diack.
Replacements: N Brady, C Black, R Lutton, N McComb, A Birch, P Marshall, N O'Connor, C Cochrane.
Treviso: B Williams, L Nitoglia, L Morisi, D La Grange, G Toniolatti, A Di Bernardo, F Semenzato, C Loamanu, D Budd, R Barbieri, C Van Zyl, V Bernabò, L Cittadini, F Sbaraglini, A De Marchi.
Replacements: G Maistri, M Muccignat, B Roux, M Fuser, M Filippucci, P Derbyshire, J Ambrosini, T Iannone.