Cliff Akurang grabbed the only goal as Histon recorded their first win of the season - and inflicted Grays' first defeat of the new campaign. The former Dagenham & Redbridge man latched on to Craig Pope's pass and tucked the ball past Grays keeper Ross Flitney three minutes after half-time.
Flitney then prevented Jamie Barker from making it 2-0 from close range.
Grays' Danny Kedwell went close with a header, while Histon keeper Mark Osborn saved James Lawson's 25-yard drive.
Grays: Flitney, Sambrook, Ashton, Stuart, Cooksey, Lawson (Marshall 73), Hearn, Barnard (Day 46), Oli, Kedwell, Watson (O'Connor 58). Subs Not Used: Knowles, McAllister.
Histon: Osborn, Pope, Ada, Mitchell-King, Gwillim, Okay, Cambridge, John Kennedy (Haniver 90), Knight-Percival, Barker (Neil Kennedy 88), Akurang (Wright 83). Subs Not Used: Naisbitt, Langston.
Goals: Akurang 48.
Ref: G Stretton (Leicestershire).