Johnathan Smith netted the only goal of the game to secure a vital three points for the Spireites.
Caretaker boss John Pemberton made three changes to the side that lost to Solihull Moors on New Years Day. Smith, Sam Wedgbury and Robbie Weir came in to replace Jay Sheridan, Jack Mckay and the injured Josef Yarney.
Tommy Wright had a couple of chances for the visitors inside the first ten minutes. First off he received a long ball over the top and sliced his strike into the side netting. A few minutes later he gained possession from Wedgbury just inside the Chesterfield half and made a terrific run into the box, eventually seeing his effort roll past the far post.
The Spireites had a great opportunity to take the lead in the 15th minute when Mike Fondop found himself one-on-one with Nik Tzanev, the striker tried to chip the Sutton ‘keeper but instead fired the ball well over the crossbar.
Despite a few chances for both sides in the opening 45, neither side managed to find the back of the net and the two teams went into the second half on level terms.
A few minutes into the second period of play, Liam Mandeville saw his free-kick pushed out for a corner by keeper Tzanev.
Just a minute later the Spireites took the lead when Fondop played a low ball into the box for Smith to curl into the right corner of the net.
On 80 minutes the U’s managed to bundle the ball into the back of the net but manager Matt Grey’s wild celebrations soon came to a halt when the referee ruled the goal out for a handball.
Three minutes later Harry Beautyman’s glancing header looked destined for the bottom left corner but Shwan Jalal got down well to make an incredible stop.
Following the full time whistle, the referee gave both Fondop and Sutton's Craig Eastmond a red card after the two were seen in the middle of a scuffle.
Chesterfield: Jalal, Weir (Denton 65), Buchanan, Evans, Hollis, Smith, Weston, Mandeville (Sharman 61), Wedgbury, Fondop, Boden (McKay 82).
Unused Substitutes: Wharton, Sheridan.
Attendance: 3,283 (90 away)