Treviso came from behind to clinch an 18-15 victory and inflict an 11th PRO14 Conference B defeat on the Dragons this season.
The Dragons had looked on course to grab victory and a four-try bonus point after hooker Liam Belcher, with two, and wing Jared Rosser scored tries.
But none of them were converted by outside half Zane Kirchner and that proved to be the difference.
Treviso scored tries from flanker Alberto Sgarbi and wing Monty Ioane in a frantic first quarter, with fullback Ian McKinley converting one of them. But two second-half penalties from fly-half Marty Banks turned the game their way.
The match began at a blistering pace with 22 points scored in the opening 15 minutes.
Rosser grabbed the first try from a neat grubber kick deep into to the corner of the Benetton try area from Kirchner.
It was all Dragons early on. Rosser forced Ioane to give up a scrum five by hassling the Benetton wing into touch in goal and big lock Rynard Landman tried to place the ball at the foot of a post for a try but dropped it.
However, the second try came soon afterwards as the Dragons rolled a maul on the Italians' line for Belcher to drive under bodies and touch down.
Neither home try was converted by Kirchner, whose attempted clearance from under his own posts moments later saw Benetton skipper Sgarbi charge the kick down and retrieved it to score.
McKinley converted and, on the quarter-hour, a ruck on the home line saw scrum-half Tito Tebaldi feed Ioane on the blindside to squeeze in for an unconverted try.
The frantic pace slowed for 20 minutes but picked up when full-back Hallam Amos just failed to ground the ball over the Benetton line before another rolling maul from an attacking line-out saw Belcher land his second unconverted touchdown.
There was not a lot of positive rugby after the break as the Dragons searched for a fourth try and a bonus point.
Yet Treviso grabbed the few opportunities that came their way as two Banks penalties before and after the hour took them from three points down to three points ahead.
From there, the match dribbled to a conclusion. Kirchner had a penalty from 40 metres, but his miserable afternoon continued as his kick slid wide of the posts.
Treviso finished on top as stern Dragons head coach Bernard Jackman looked on from the stands.
Two tries for the Italians were ruled out in the final minutes as they secured an eighth league win and left the home side with only a second losing bonus point of the season for their efforts.