A dramatic late try put Crusaders firmly in the hunt for an end of season play-off place in just their second Super League season.
The victory puts Brian Noble’s side just two points off a top eight spot, as the race for the play-offs heats up with just five rounds to go.
First, a pin-point Bosc kick was gathered by the France international full-back for him to touchdown, before a nice short ball sent the former St George man through a gap to give Catalans a 12-6 lead.
As the first half drew to a close, Crusaders put the home side under more pressure, and were rewarded when Jason Chan charged through for a try, converted by Clinton Schifcofske to tie things up at 12-12.
The game continued in its see-saw vein in the second, with Rhys Hanburg and Remi Casty exchanging converted tries, before a Bosc penalty edged Catalans 20-18 in front.
A high tackle gave Crusaders the chance to even the game up once again, which they did through Schifcofske with less than ten minutes remaining, only for Bosc to add another two pointer of his own and give Catalans a 22-20 advantage.
But from the resulting kick-off, Vince Mellars recovered the ball and set the platform for first Sammut and then Lupton to carve open the Dragons back line and record a notable win for the Welsh club.