Wing Jonah Holmes grabbed a brace of tries but Dragons suffered a disappointing 26-15 defeat in Italy as Zebre secured victory in the Guinness PRO14 clash at Stadio Sergio Lanfranchi.
A disjointed first half saw Ben Fry and Ross Moriarty sent to the sin bin as Zebre pulled away and into a 16-3 lead.
Zebre extended the lead through Lorenzo Masselli and despite a late try double from Wales international Holmes it was the Italians who took the victory.
The win for Michael Bradley’s team saw them leapfrog Dragons and Glasgow in the table while the result left Dean Ryan’s men hunting a return to winning ways ahead of the derby with Ospreys next weekend.
Dragons made a late change before kick-off with back row Moriarty coming in as a replacement for Huw Taylor to make his first appearance since October.
Ryan’s men started brightly but after missing the chance to score inside two minutes through a driving lineout move it was Zebre who struck first.
Number Eight Giammarioli spotted a gap in the defensive line and brushed off tackles to score a converted try under the posts.
Home playmaker Pescetto then saw a penalty from halfway slide wide right to issue Dragons with a warning that they could ill afford to give away needless penalties.
Ashton Hewitt and Jordan Williams looked to inject pace before the busy Holmes just failed to keep a searching cross field kick from Sam Davies in play.
Fry was yellow carded for an infringement at the breakdown and Pescetto added three points to stretch the home lead.
Scrum half Gonzalo Bertranou, on his debut, showed his alert play to take a quick tap penalty inside the home 22 and try and catch Zebre napping.
But the chance went begging as Dragons were shunted off the ball by a physical Zebre defence.
Moriarty produced a monster carry on the halfhour before Davies spotted space in behind for an intelligent grubber that secured a five-metre lineout.
However, the driving maul was quickly sacked as Zebre escaped a period of pressure with just a Sam Davies penalty against them.
Pescetto added two more kicks before the break with Moriarty the latest to fall foul of referee Gianluca Gnecchi for a no arms tackle.
Zebre went straight on the attack after the break and, with the numerical advantage, saw a try chalked out for a foot in touch after a superb covering tackle buy Dixon.
The home side did add a second, though, when a neat offload in the tackle exploited numbers and back row Lorenzo Masselli raced in and Pescetto converted from the touchline.
Ryan started to empty his bench in the search for a dramatic comeback and Rhodri Williams almost latched onto a searing break by namesake Jordan.
Holmes did make it count when he sliced his way over after a huge looping backdoor pass from Rhodri Williams,. Davies added the extras to ignite fresh hope in the final quarter.
A late penalty from Antonio Rizzi saw followed by a second score from Holmes as he again showed his finishing skills. Dragons pushed late on from deep but when Holmes was checked looking to pounce on a chip the game was finally over.
08m Giammarioli t Pescetto c 7-0
16m Pescetto p 10-0
28m Davies p 10-3
33m Pescetto p 13-3
39m Pescetto p 16-3
51m Masselli t Pescetto c 23-3
67m Holmes t Davies c 23-10
78m Rizzi p 26-10
79m Holmes t 26-15
Zebre: Michelangelo Biondelli, Pierre Bruno, Tommaso Boni, Enrico Lucchin, Gabriele Di Giulio, Paolo Pescetto, Marcello Violi, Daniele Rimpelli, Oliviero Fabiani, Eduardo Bello, Samuele Ortis, Ian Nagle, Lorenzo Masselli, Potu Junior Leavasa, Renato Giammarioli.
Replacements: Massimo Ceciliani, Paolo Buonfiglio, Matteo Nocera, Mick Kearney, Jimmy Tuivaiti, Nicolò Casilio, Antonio Rizzi, Jamie Elliott.
Dragons: Jordan Williams (Lewis 66), Jonah Holmes, Aneurin Owen, Jack Dixon (Roberts 50), Ashton Hewitt, Sam Davies, Gonzalo Bertranou (Williams 60); Greg Bateman (Reynolds 60), Ellis Shipp (Hibbard 60), Lloyd Fairbrother, Ben Carter (J. Davies 66), Joe Maksymiw, Harrison Keddie, Ben Fry (Baker 49), Ross Moriarty
Replacements: Richard Hibbard, Josh Reynolds, Aaron Jarvis, Joe Davies, Dan Baker, Rhodri Williams, Josh Lewis, Jamie Roberts
Referee: Gianluca Gnecchi (FIR, 6th competition game)