Calvisano (10) 17
Tries: Garcia, Bernabo Cons: Fraser, Raineri Pen: Fraser
Dragons (28) 42
Tries: Fussell, Charteris, Smith, Black 2, Sidey Cons: Arlidge 6
Adam Black scored his 24th try in the last of 163 Dragons appearances
Newport Gwent Dragons comfortably earned the 24th and final Heineken Cup place for next season with this play-off win at Calvisano.
The Italian club led through an early Gerard Fraser penalty, but the rest of the night belonged to the Dragons.
Richard Fussell, Luke Charteris, Ashley Smith and Adam Black scored first-half tries to which Gonzalo Garcia replied.
Rory Sidey and Black crossed after the break, Valerio Bernabo replying. James Arlidge kicked 12 Dragons points.
The Dragons go off to a nervous start as the hosts took the game to the Welsh team, who had finished second-from-bottom in the Magners League in ninth and last of their nation's regional teams.
That is what led them to Centro Sportivo San Michele for the play-off and in the circumstances the Dragons' edginess was understandable.
Calvisano deserved the lead fly-half Gerard Fraser's boot brought after seven minutes, his penalty from 40 metres rewarding his side's solid start.
But a minute later the visitors' shakiness disappeared as Scarlets-bound prop Rhys Thomas's crafty footwork paved the way for wing Fussell to cross and Arlidge to convert.
A Dan Lydiate charge down enabled towering Wales lock Luke Charteris to get into an impressive stride and even more impressive stretch to place the ball over the line.
Arlidge converted the 13th-minute try and added a third conversion after Ashley Smith broke through.
But Dragons' fans raised their biggest cheer of the night for prop Adam Black, 34, who crossed for his 23rd try in the last of his 163 appearances before leaving Rodney Parade.
Arlidge again converted to give the Dragons a lead made a little less comfortable by Calvisano's solitary first-half response, a well-taken try by wing Gonzalo Garcia who powered past Fussell to touch down. Fraser converted.
The Dragons withstood a determined onslaught from the Italian side in the third quarter, but as Calvisano's attempts to get back into the game became ever-more desperate so their mistakes multiplied.
It was no surprise to see Dragons centre Rory Sidey pounce on some loose Calvisano play deep in the hosts' 22, Rodney Parade-bound prop Ali McKenzie's final fumble allowing the Australian a simple score. Arlidge converted.
Gareth Wyatt was denied by a foot in touch at the corner, but Black was not to be denied as he again ploughed over from close range in the 73rd minute and Arlidge converted.
Calvisano claimed a consolation try at the end, Bernabo crossing and Giovanni Raineri converting.
Dragons boss Paul Turner:
"I'd be liar to say it wasn't a relief [to earn Heineken Cup qualification].
"We haven't played for two weeks and we've had six or seven major injuries so to come over here facing a side who are always good on their own patch - they hadn't lost in the league this season - and with 10 internationals in their team
so yeah, it was a great performance.
"It won't happen again, will it [a play-off]? I think next season it will be top three Welsh regions go through to Europe and the fourth one goes into the shield [European Challenge Cup] so we probably won't get this opportunity if we come fourth next year, which obviously we intend not doing.
"But it was always going to be difficult and we had a cracking first half and played some good stuff - as good as we've played most of the season and the game was virtually over at half-time."
Calvisano: Luke Mclean; Winston Mafi, Matteo Pratichetti, Gonzalo Garcia, Ludovico Nitoglia; Gerard Fraser, Paul Griffen; Alistair McKenzie, Leonardo Ghiraldini (capt), Hoani Tui, Peter Sidoli, Cameron Treloar, David Dal Maso, Aaron Persico, Alessandro Zanni.
Replacements: Ben Evans, Tommaso D'Apice, Valerio Bernabo, Nicola Cattina, Pino Patelli, Giovanni Raineri, Paolo Buso.
Dragons: Jason Tovey; Gareth Wyatt, Rory Sidey, Ashley Smith, Richard Fussell; James Arlidge, Wayne Evans; Adam Black, Tom Willis (capt), Rhys Thomas, Hoani MacDonald, Luke Charteris, Dan Lydiate, Craig Hill, Lewis Evans.
Replacements: Steve Jones, Nigel Hall, Grant Webb, Andrew Hall, Alex Walker, Aled Brew, Martyn Thomas.
Ref: Dave Pearson (Newcastle).