Sheffield United slipped out of the automatic promotion places in League One after falling to a 4-0 defeat at the hands of Stevenage.
A hat-trick from Daniel Lopez and a Lucas Akins strike condemned Danny Wilson's side to defeat at the Lamex Stadium.
Brentford took advantage of United's slip-up and moved into second place in the table following Sam Saunders's late winner in their game against Preston North End.
League One Leaders Doncaster Rovers missed the opportunity to extend their lead at the top of the table as they could only draw 1-1 with Portsmouth at the Keepmoat Stadium.
At the other end of the table Colchester United earned a precious 2-1 win over Bury that moved them seven points clear of the relegation zone.
Meanwhile, defeats for Hartlepool and Oldham at the hands of Coventry and Bournemouth respectively increased their relegation woes.
Results in full: Brentford 1-0 Preston North End, Bury 1-2 Colchester United, Coventry City 1-0 Hartlepool United, Crewe Alexandra 1-1 Shrewsbury Town, Doncaster Rovers 1-1 Portsmouth, Leyton Orient 4-1 Carlisle United, MK Dons 3-0 Tranmere Rovers, Notts County 1-0 Scunthorpe United, Oldham Athletic 0-1 Bournemouth, Stevenage 4-0 Sheffield United, Walsall 2-2 Crawley Town
