The visitors were forced to play the last half-an-hour with 12 men after Robinson was sent off by referee James Child for making contact with full-back Morgan Escare's head in an off-the-ball tackle.
They were trailing 16-14 at the time but rallied magnificently to produce a rousing finale and extend their winning run to five matches.
Centre Joe Wardle scored two of their five tries but the architect of their impressive triumph was skipper Danny Brough, whose tactical kicking kept his side on the front foot for most of the match.
Aaron Murphy, Leroy Cudjoe and Shaun Lunt also crossed for the Giants with Brough kicking four goals.
Jean Philippe-Baile, Eloi Pelissier, Zeb Taia and Frederic Vaccari crossed for the French outfit.
Salford made it a triumphant start for new coach Brian Noble with a 34-20 victory in their Super League basement battle against Castleford Tigers.
The visitors led 30-28 until Ryan McGoldrick intercepted a Rangi Chase pass nine minutes from time to seal a thrilling win with Marc Sneyd booting his fifth conversion.
Matty Ashurt, Danny Williams, Andrew Dixon, Vic Mauro and Theo Fages also went over for the Reds,
Nathan Massey, Justin Carney, Adam Milner, Oliver Holmes, Jamie Ellis and Jordan Thompson replied for Castleford with Ellis adding three goals.