A third win in four moved Chesterfield up from 11th to the cusp of the play-offs, as Doncaster Rovers, Fleetwood Town and Peterborough United all lost on Tuesday.
The Spireites face Posh on Saturday in a seventh versus eighth clash in League One with the visitors to London Road full of confidence after a 3-0 win over Gillingham.
A resurgent Peterborough, under caretaker manager Dave Robertson, lost 2-0 at second-placed Preston North End, who are at sixth-placed Barnsley this coming weekend.
Doncaster have fallen away from the play-off picture after a 2-1 defeat on home soil to third-placed Swindon Town, while Fleetwood lost 2-0 at home to Coventry City.
There were draws for both Sheffield United, in fifth, at Walsall and Barnsley at Leyton Orient, as five points separate eight teams bidding for two play-off spots.
Tuesday’s Results: Bristol City 3 Crewe 0; Chesterfield 3 Gillingham 0; Colchester 2 Yeovil 0; Doncaster 1 Swindon 2; Fleetwood 0 Coventry 2; Leyton Orient 0 Barnsley 0; Notts County 1 Rochdale 2; Oldham 1 MK Dons 3; Port Vale 2 Crawley 3; Preston 2 Peterborough 0; Walsall 1 Sheff Utd 1.
Saturday’s Fixtures: Barnsley v Preston; Bradford v Fleetwood; Coventry v Doncaster; Crawley v Leyton Orient; Crewe v Oldham; Gillingham v Colchester; MK Dons v Notts County; Peterborough v Chesterfield; Rochdale v Scunthorpe; Sheff Utd v Port Vale.