Walsall kept up their perfect home record by crushing Peterborough despite having Anthony Gerrard sent off.
Walsall were 3-0 up before the half-hour thanks to Daniel Fox's shot and Michael Dobson helping himself to goals in the 17th and 27th minutes.
Dobson turned home Kris Taylor's cross and then scored with a low shot.
Just past the hour Gerrard was sent off for a high tackle, but Martin Butler's header made it 4-0 and he claimed a second with a low drilled effort.
Walsall: Ince, Westwood, Gerrard, Roper, Taylor, Wright, Dobson, Keates (Demontagnac 90), Fox, Butler (Bedeau 81), Sam (Kinsella 66).
Subs Not Used: Fangueiro, Gilmartin.
Sent Off: Gerrard (63).
Goals: Fox 7, Dobson 17, 27, Butler 75, 79.
Peterborough: Tyler, Holden, Arber, Branston, Newton, Butcher, Gain (Stirling 55), Carden, Day (Ghaichem 77), Opara (Crow 47), Benjamin.
Subs Not Used: Richards, Huke.
Sent Off: Carden (87), Branston (88).
Booked: Branston, Carden.
Ref: J Singh (Middlesex).