Northampton added to managerless Shrewsbury's problems with a comprehensive victory at Greenhous Meadow.
Paul Anderson scored twice as the Cobblers produced a strong away performance against a side who remain bottom of League One.
The visitors almost took an early lead but Anderson's header produced an excellent save from goalkeeper Jayson Leutwiler.
Louis Dodds then went close to a Shrews breakthrough but his close-range effort was impressively blocked by Cobblers keeper Adam Smith.
Northampton edged ahead in the 22nd minute when central defender Gabriel Zakuani headed in a corner from Jak McCourt.
The visitors doubled their advantage nine minutes later when winger Anderson turned the ball home at the far post following a fine run and left-wing cross from JJ Hooper.
Shrewsbury reduced the arrears in the 36th minute, Ivan Toney confidently firing home a penalty against his former club after being brought down by Zakuani.
Northampton restored their two-goal advantage in the 65th minute with Sam Hoskins slamming home a low volley from the edge of the penalty area.
Anderson then added a fourth a minute from time with a 15-yard effort which beat Leutwiler low to his right.
Toney pulled another goal back deep into stoppage time when he converted his second penalty after McCourt's challenge on Junior Brown.
Report supplied by the Press Association
