A solitary goal by Chris Saunders saw Cray overcome a battling Hastings team whose left back Ross Sutton had to play in goal after their regular 'keeper Matt Armstrong-Ford reported sick.
On 18 minutes Sutton pushed out a searching cross from Cray's left winger Jack Clark, but the ball went straight to Saunders who drove it into the net.
Clark had rattled the woodwork with his first-minute free-kick from the edge of the penalty area, while Danny Young's crunching tackle had stopped Tamer Tuna when he looked set to score for Hastings in the 9th minute.
Cray made the best chances in the first half, with Leigh Bremner firing over the bar and Saunders, again lurking with intent, clipping his shot wide when another loose ball ran to his feet.
A scrappy second half saw Cray threaten only from occasional breakaways, with Tommy Whitnell missing a good chance when he did everything right but then chopped the ball into the side-netting after taking the ball round the 'keeper.
Bremner was twice frustrated when he broke into the goalmouth, firstly seeing the referee ignore his claims for a penalty when he seemed to be tripped from behind, and then seeing Sutton push away his close-range effort.
Tony Dolby, a former Hastings manager, made a vital defensive contribution as Cray's substitute, clearing Joe Barham's cross out of the goalmouth and then heading away the resultant corner-kick as the visitors mustered some late pressure.
The three points took Cray back into the play-off zone, holding fifth place, with an away trip to second-from-bottom Aveley to come next Saturday (3pm).
Cray: Walker, Young, Bentley (Dolby 73), Saunders, Vines, Sterling, Whitnell (Parkinson 73), Perkins, Bremner, Phillips, Clark. Subs not used: Hall, Norton, Power