Hull ran in six second-half tries to overturn a 16-12 half-time deficit and get their Super League campaign off to a winning start but the Dragons had a chance to pinch a point from a dramatic match after scoring a last-minute try.
The Black and Whites appeared to have the game won when they led 36-22 after 75 minutes but the Catalans struck back with three tries in a remarkable finale.
Thomas Bosc would have earned a share of the spoils had he managed to convert Zeb Tai's last-minute try but he was off target for the fourth time in seven attempts to leave Hull 36-34 winners at the KC Stadium.
Hull's goalkickers fared even worse, with Joe Westerman and Ben Crooks managing just two successes from eight attempts between them.
Australian stand-off Jordan Rankin was the hero for the Black and Whites on his debut, scoring a long-range try and creating two others in a crucial seven-minute spell in the second half, while centre Kirk Yeaman scored twice, taking his try total for the club to 157 and climbing to fifth in the all-time list.
The Catalans were on course for their first win at the KC Stadium since 2008 after dominating the first half but coach Laurent Frayssinous will be alarmed at the way his side collapsed after the break.
Thomas Bosc, who was preferred to Scott Dureau as the half-back partner for Leon Pryce, and Morgan Escare, who got the nod at full-back ahead of another overseas player Brent Webb, were the architects of the Dragons' dominant first-half display.
An early 40-20 kick from Bosc enabled the visitors to set the tone and they led from the 12th minute when winger Damien Cardace took Escare's pass to touch down one-handed for the first of his two tries.
Bosc then shrugged off the discomfort of a heavy nose bleed to hoist a pin-point kick which second rower Elliott Whitehead plucked out of the air to touch down for the Dragons' second try on 19 minutes.
The French international stand-off added the goal but was off the field having treatment for his nose injury when Hull scored their first try, Whiting finishing off neat handling by Westerman and Danny Houghton.
Westerman's goal cut the deficit to four points but the Catalans exposed another chink in Hull's right-side defence on 27 minutes as Cardace gathered Escare's long pass to cross unopposed for his second score.
Cardace then turned hero at the other end of the pitch by getting a hand to Richard Horne's pass to ruin Hull's two-man overlap but the home side managed a second try five minutes before half-time when the influential Whiting slipped a superb pass out of the tackle for centre Kirk Yeaman to touch down.
Hull's discipline continued to let them down in the second half and the Dragons almost made them pay when second rower Zeb Tai was thrown back from the line after clever work from Leon Pryce.
They survived that scare, however, and began to look the livelier side with Rankin imposing himself on the game.
Full-back Jamie Shaul was inches away from touching down Rankin's kick before the Black and Whites drew level through Yeaman, who collected Rankin's pass after Catalan centre Ben Pomeroy went for the interception.
Rankin then produced the defining moment of the match, taking Whiting's offload and eluding Escare on a 50-metre sprint to the line.
The purple patch was complete when Cardace failed to gather Rankin's crossfield kick to present Hull winger Tom Lineham with an easy try.
Westerman could not convert any of the three tries but Hull began to look comfortable leading 24-16 and they quickly put the game to bed.
Substitute Jordan Thompson charged through a woeful defence to score with his first touch of the ball on his debut and centre Ben Crooks carved out a try for veteran scrum-half Richard Horne.
Crooks had no more joy when he took over the goalkicking from Westerman but he scored Hull's eighth try after collecting Horne's kick.
The Dragons appeared to be well beaten but they added some respectability to scoreboard with three tries in the last 12 minutes.
Pryce created one for Tai before Cardace completed his hat-trick and there was still time for Escare to go over to cut the gap to six points with three minutes left.