Jon Obika fired Yeovil out of the relegation zone and dumped Northampton into the bottom four.
Glovers boost survival hopes
Spurs loanee Jon Obika scored his second goal in four games to lift Yeovil out of the relegation zone and dump Northampton into the bottom four.
He struck in the 79th minute after substitute striker Luke Rodgers had played him through with an incisive through ball.
Yeovil should have doubled their lead four minutes later when Andy Welsh was clean through but Chris Dunn came out to block with his legs.
Northampton almost salvaged a point when Danny Jackman hit the far post with a right-wing free-kick, the ball bouncing back into the arms of goalkeeper Chris Weale who kept his third clean sheet since a loan move from Bristol City.
A string of fine saves from goalkeeper Dunn robbed Nathan Smith and Obika of early goals but Yeovil lacked the finishing touch until Obika's late strike.