Cobblers picked up what could prove to be a valuable away point when held to a goalless draw by in-form promotion rivals Sutton United on Saturday.
Town edged the first-half at Gander Green Lane but were on the back foot in the second until home skipper Craig Eastmond saw red with 16 minutes to play.
That put the onus on Northampton to try and find a winner but again they were undone by a lack of quality and composure in the final third and had to make do with a point.
Although it feels like a missed opportunity, Cobblers did become the first away team to pick up a point at Sutton since October and only the second side to stop them scoring at home, enough to keep them in fourth place in an extremely congested League Two table.
Chanka Zimba made his first start for the Cobblers after replacing Dylan Connolly in the only change from last weekend's draw with Forest Green.
Manager Jon Brady sprung a surprise by tweaking his formation again, this time opting for a midfield diamond with Mitch Pinnock at the tip behind a front two of Zimba and Sam Hoskins.
After a subdued start, the game broke into life with a hectic passage of play on 15 minutes.
Jon Guthrie headed a Pinnock corner straight at Dean Bouzanis and Sutton immediately broke at speed through the menacing David Ajiboye. He got to the byline and delivered a cross that was only cleared as far as Alistair Smith, whose volley was brilliantly kept out by Liam Roberts low down to his right.
Then followed a big opportunity for Zimba to open his Cobblers account but after engineering the chance well, he took a slightly heavy touch and goalkeeper Bouzanis was quick off his line to smother.
Sutton also survived a scramble in their penalty area following an excellent last-ditch block on Zimba, but those moments aside, there was not a lot to excite either set of supporters in a cagey first-half.
The hosts should have been ahead within 90 seconds of the restart as a glorious chance fell to Will Randall, but his header was too close to Roberts and Town's goalkeeper pulled off another excellent save.
Sutton upped their intensity levels in the second-half and had Cobblers pinned back, though there was not much else to worry Roberts.
The home side's momentum was significantly checked with 15 minutes to go when, to everyone's surprise, Eastmond was sent for an early bath. His high challenge on Pinnock seemed innocuous at the time but, after consulting with fourth official Trevor Kettle, referee John Busby brandished a straight red card.
The onus was now on Northampton and they did have their chances as Aaron McGowan's low cross flashed across the six-yard box and away to safety before Danny Rose shot wide with the clearest opportunity from the centre of the box.
But in truth they did not really create enough to deserve all three points, and when Hoskins headed onto the roof of the net deep into stoppage-time, the chance to snatch victory was gone.
Sutton: Bouzanis, Goodliffe, John, Kizzi, Milsom, Smith, Randall, Eastmond (c), Ajiboye (Boldewijn 72), Olaofe (Davis 76), Bugiel (Bennett 90)
Subs not used: Nelson, Barden, Wyatt, Davis, Wilson
Cobblers: Roberts, McGowan, Horsfall (c), Guthrie, Koiki, McWilliams, Sowerby, Lewis (Connolly 89), Hoskins, Pinnock, Zimba (Rose 58)
Subs not used: Maxted, Harriman, Magloire, Mills, Flores
Referee: John Busby
Cobblers fans: 500