Morecambe recorded their first home victory of the season as Chesterfield left the Globe Arena empty-handed.
Gary McDonald's far-post volley from Richard Brodie's left-wing cross put the hosts ahead just before half-time.
Brodie also set up the second goal, getting the better of Terrell Forbes, and Lewis Alessandra volleyed past Richard O'Donnell from close range.
Craig Westcarr twice went close for Chesterfield, while Neal Trotman put a free header wide.
VIEW FROM THE DRESSING ROOM
Morecambe manager Jim Bentley told BBC Radio Lancashire:
"There wasn't much in it in the first half. We were evenly matched, but goals change games.
"We got the goal at the crucial time, we came out in the second half and scored a great second goal.
"We could have had one or two more but I'll take 2-0, a clean sheet, three points and the right result."
Chesterfield caretaker manager Tommy Wright told BBC Radio Sheffield:
"For the first 40 minutes I was delighted. I thought we broke, created chances.
"In the second half, we were not good enough, we were second best all over the park.
"Morcambe were far the better team in the second half and we looked like we lost heart."
Morecambe 01 Roche 02 Fenton 03 Threlfall Booked (Haining - 59' ) 08 Wright 15 McCready 16 Drummond 17 Fleming 18 McDonald 09 Alessandra 10 Brodie 27 Redshaw (Burrow - 80' Booked ) Substitutes 25 Arestidou 06 Haining 24 James Short 07 Reid 19 McGee 20 Mwasile 14 Burrow Chesterfield 13 O'Donnell 04 Forbes Booked 05 Trotman 06 Hird 12 Darwikwa 16 Ridehalgh 08 Togwell 10 Whitaker (Evans - 61' ) 17 Atkinson (Allott - 62' ) 25 Talbot 11 Westcarr (Lester - 78' ) Substitutes 27 Wilson 07 Allott 15 Clay 14 Lester 18 Boden 19 Hazell 29 Evans