The Cobblers’ plight remains as stark as ever following a fourth straight home defeat, this time to Plymouth Argyle, who won at Northampton for the first time since 1951.
The Pilgrims ran out 2-0 winners at Sixfields courtesy of first-half goals from Reuben Reid and Lewis Alessandra in a match played in a gale.
As a result, Northampton are now seven points adrift of safety at the bottom of the Football League with concerns continuing to grow about their ability to stay up.
Four players, newly arrived under new manager Chris Wilder, made their full home debuts but they had barely had time to break a sweat when Plymouth took the lead.
There appeared to be little danger when the ball was fed into the box from the Argyle right and at least one defender should have cut it off before it arrive at Reid’s feet.
From there, he was given space to turn and although his connection on the shot was not clean, it still squirmed under Duke.
The Town goalkeeper, so influential in the first half of the season, has been in patchy form lately and this was another error on his part.
It might have been two shortly afterwards.
Firstly, Duke turned a weak Jason Banton shot around the post after a swift counter-attack and then the same player avoided the offside trap at the second phase of a corner only to see his hurried shot drift wide of the target.
The Cobblers’ first good chance came after 35 minutes and through their first good piece of play.
Lee Collins collected a through-ball while facing his own goal, turned on it and passed to Alan Connell, who dropped his shoulder to lose his marker and thread in Emile Sinclair.
The angle was not entirely in the striker’s favour but he should have done better than the lashed effort that cleared the crossbar by a good five yards.
The second goal, though, went to Plymouth and, again, was entirely avoidable.
Chris Hackett needlessly conceded a corner that went short to Lewis Alessandra to cross into the box right-footed.
The low, skimming pass appeared as though it would be thumped away by Emile Sinclair but he inexplicably pulled his foot away and the ball dropped in at the far post.
Town started the second half much better, and with the benefit of the wind began to enjoy some decent spells.
But shots at goal were few and far between - Hackett attempted to score directly from a corner but Jake Cole expertly blocked the effort.
And the end result was another depressingly inevitable defeat.
Cobblers: Duke, McSweeney, Collins, Doumbe, Widdowson, Hackett, Ravenhill, Carter, Dickenson, Connell, Sinclair
Subs: German (for Collins 68)
Not used: Morris, O’Donovan, Tozer, Snedker, Deegan, Robertson
Plymouth: Cole, Blanchard, Nelson, Trotman, Purrington, Alessandra, Blizzard, Hourihane, Banton, Reid, Boco
Subs: Harvey (for Banton 71)
Not used: Young, Wotton, Thomas, Richards, Vassell, Dawson
Away fans: 766