The substitute struck in the 64th minute to settle a tight contest, with the Railwaymen’s success being their third in the last four games as they move into the play-off places, up to seventh.

Early on Tommi O’Reilly’s cross was scrambled away from Josh March before Robbie McKenzie wasted a good shooting chance for the visitors when screwing an effort wide after Ronan Hale’s pass played the midfielder through the middle.

McKenzie then made a vital intervention to dispossess Calum Agius as the attacker shaped to shoot.

Crewe goalkeeper Ian Lawlor made two important first-half stops, diverting Hale’s angled effort away with a leg and thwarting veteran striker Sam Vokes, who rose highest at the back post to plant a firm header from a corner on target.

Agius should have added the finishing touch to an O’Reilly cross, but at full stretch at the far post, the attacker somehow managed to flick the ball wide.

Vokes went close again just after the hour mark when his deflected flick on Max Clark’s cross flew past the far corner.

But it was Thibaut who produced the decisive moment, reacting the quickest after Mickey Demetriou’s set-piece header fell loose inside to drive a low shot into the far corner.

Gills goalkeeper Glenn Morris pushed out a later effort from O’Reilly.