The Spireites lost 2-1 at the Proact.
Chesterfield were unable to make it three home wins on the bounce over the weekend.
John Sheridan's men lost 2-1 against Eastleigh, despite taking the lead just after a quarter of an hour.
Sixteen minutes in, Gevaro did well on the left, before clipping a ball into the box, which was nodded in by Tom Denton.
The visitors levelled on the brink of the interval, when Tyrone Barnett found himself unmarked in the Chesterfield penalty area to head the ball beyond Shwan Jalal following a long throw-in.
Marcus Barnes then struck the winner for Eastleigh ten minutes into the second half.
A defensive mix-up involving Gevaro and Curtis Weston allowed Barnes the opportunity to put the away side in front.
Anthony Spyrou and Mike Fondop were introduced late on, but the hosts were unable to find an equaliser.
Afterwards, Manager John Sheridan expressed his frustration at his side's lack of concentration at key moments;
"We've got to get a grip of each other. We need to switch on more-for us to let in a goal just before the break like that was so disappointing.
"We haven't reacted quickly enough for either of their goals, you've got to be more positive than that."
It leaves Chesterfield twenty-second in the National League table-three points from safety.
The Spireites return to action tomorrow evening against AFC Fylde.