The Robins suffered their first loss of the seasons at the hand of Chesterfield at the Proact Stadium.
Gary Roberts' deflected shot earned the home side a 1-0 lead going into the break. Byron Harrison came closest to leveling for Cheltenham as he saw his shot beat the keeper but cleared off the goal-line.
Troy Brown had the ball in the back of the net in the second half but his effort was ruled out for offside.
Substitute Oein Doyle secured the three points for the home side as the clock ticked over into additional time. Doyle was afforded time and space on the edge of the box to fire a deflected shot past Scott Brown.
Despite the result, the Robins shot-stopper had an excellent game between the sticks. His efforts in goal largely limiting the Spireites goal tally to just two.
Robins manager Mark Yates stuck by the same team that started the match against Crawley in midweek.
Byron Harrison remained in partnership with Terry Gornell after scoring 3 goals since replacing Jamie Cureton just 20 minutes into the opening day of the season.
Today's fixture was Chesterfield's first home fixture of the season and their manager, Paul Cook, made two changes from the team that lost 2-1 at Leeds United in the cup on Wednesday.
Eoin Doyle was replaced by Marc Richards and Joy O'Shea joined the starting 11 as Tendayi Darikwa droped to the bench.
Marc Richards was keen to add to his goal tally after finishing as the Spireites top scorer last season.
He started the game brightly, first chasing down a long ball and crossing into an empty 18-yard box before heading marginally wide from six yards after a perfect cross from Gary Roberts.
The Robins weren't disheartened following the home sides good opening spell.
Harrison rolled the ball just wide from the edge of the box and Russ Penn was able to test Tommy Lee from range.
McGlashan headed just over as he came close to taking the lead. Sido Jombati made himself plenty of space on the right wing and his looping cross was headed just over the bar.
Shortly after the winger's curling effort from range dropped just wide of Lee's left hand upright.
The home side had started the brighter and took the through Gary Roberts.
The attacking midfielder was making the most of his free reign on the field. He exploited the off-side trap on the left wing, advancing unchallenged into the Robins 18-yard box his powerful shot deflected past Scott Brown for the first goal of the afternoon.
He almost doubled the Spireites lead immediately after. The playmaker's late run into the box was picked out by Nathan Smith's cross. Roberts looked destined to score his second but couldn't time his shot well enough and the ball was well cleared.
With Richards, Smith and Talbot all creating plenty of opportunities in and around the box, Chesterfield failed create any further meaningful chances before half-time.
Richards' hopeful overhead kick was comfortably collected by Brown and the striker tested him once more from range.
Roberts' direct free kick tested Brown in the closing stages of the half but the ever present shot stopper parried his effort away from goal with relative ease.
Just before half time, Byron Harrison came closest to scoring for the Robins in the first half.
He was denied by a goal line clearance after beating Tommy Lee in the Chesterfield goal. The striker had capitalised on a defensive error in the Spireites back line and slid the ball past the sprawling keeper.
And on the stroke of half time, McGlashan fired over from 18-yards, having to react quickly recieving Matt Richards' free kick.
Half Time: Chesterfield 1 - 0 Cheltenham Town
The second half started slowly, Joy O'Shea came clsest in the opening exchanges as his low drive forced Scott Brown into an excellent save.
Terry Gornell was replaced by Ashley Vincent seven minutes after the restart, the striker went down in the centre circle of his own accord.
Cheltenham had the ball in the net shortly after, and the game sparked into life.
However, Troy Brown's header was ruled out for off side as it passed the stranded Tommy Lee and ruffled the netting.
Byron Harrison came close for the visiting Robins as he beat several defenders in the Spireites 18-yard box. His jinking run ultimately denied by the on-rushing Tommy Lee as a last resort.
The Robins were able to commit men forward, and looked threatening in attack even if unable to create a clear cut chance.
However, their willingness to commit players forward often left the Robins exposed defensively.
Darwika's neat one-two with Doyle earnt enough space in the box to force an excellent save by the advancing Scott Brown.
O'Shea had the crowd on their feet as his right footed shot bends away from goal. Was again involved, beating Brown and Elliott in the Robins box only to be denied by the chest of Scott Brown.
Their chance's kept on coming, Doyle shot into the side netting and Roberts shot wide as the game entered the final 10 minutes.
Zack Kotwica was introduced by Mark Yates to give the squad a more attacking dimension.
The young winger tried to create space on the edge of the box to line-up a shot, but intelligently played the ball to McGlashan on the wing to cross back into the area.
He was involved again, sprinting down the left wing and drew a foul from Drew Talbot. What ensued was a sequence of air shots as the ball bounced around the Spireites 18-yard box, unable to send a shot goalwards.
As the clock ticked into additional time, the home side doubled their lead.
Eoin Doyle was afforded time and space on the edge of the box and his deflected shot fell just out of reach of Scott Brown for Chesterfield's second goal of the afternoon.
With 4 minutes added neither side were able to generate a shot on target as the game fizzled to its conclusion.
Full Time: Chesterfield 2 - 0 Cheltenham Town
Chesterfield (4-4-2): Lee; Talbot (c), Edwards, Hird, Smith (Darikwa '46); Ryan, Morsy, O'Shea (Togwell '84), Humphreys, Roberts; Richards (Doyle '55).
Subs Not Used: Chapman, Cooper, Ganduillet, Brown.
Cheltenham Town (4-4-2): S. Brown; Jombati, T. Brown, Elliott, Braham-Barrett; Deering (Kotwica '78), Penn (c), Richards, McGlashan; Harrison, Gornell (Vincent '52).
Subs Not Used: Lowe, Taylor, Roberts (GK), Inniss, Jones.
Referee: Michael Bull.
Star Man: Scott Brown