Blues frustrated against League Two's bottom club
Pompey were unable to breach Northampton’s defence and had to settle for a point against the Football League’s basement club.
It was not a match full of chances, but the Blues did have a couple of periods of pressure that they were unable to capitalise on.
Jed Wallace went closest to grabbing a goal early in the game, but was denied by the woodwork.
Richie Barker made one enforced change from the side that beat Dagenham & Redbridge on Boxing Day.
Skipper Johnny Ertl returned to the Blues midfield, with the injured Simon Ferry (hamstring) making way.
Ricky Holmes impressed against the Daggers and soon found some early joy down the left before cutting the ball back.
But there was only one blue-shirted player in the area and Matty Harriott was able to hack clear.
Wallace was then inches away from breaking the deadlock on 10 minutes, turning neatly on the edge of the box and sending a dipping shot crashing onto the crossbar.
And Padovani went close to scoring his second goal in as many games soon after, volleying narrowly wide from 20 yards after being picked out by Holmes.
Northampton then almost had the ball in the back of the net – not that it would have counted.
Gary Deegan’s long throw bounced over Trevor Carson and clipped the crossbar before going out of play.
But it was Pompey looking the more likely to open the scoring and Luke Norris had to make a brave challenge to deny Patrick Agyemang after Kevin Amankwaah had made a mess of clearing Holmes’ low cross on 29 minutes.
The Blues failed to make the most of their spell of dominance, however, and the half started to meander towards its conclusion.
There was almost a late twist in the tale, but Sonny Bradley’s low drive was deflected wide after Holmes’ corner had found the defender in space.
Half Time: Pompey 0 Northampton 0
The start of the second half did not exactly liven up proceedings, despite the best efforts of Holmes to get things going.
But it was the Cobblers who finally injected some life into proceedings on 57 minutes.
Pompey failed to properly clear a corner and when the ball was sent back into the box, Lee Collins flicked it on for substitute David Moyo, who forced Carson to show quick reflexes.
The hosts then raced straight up the other end of the pitch and Thery Racon saw his drive blocked.
But the Fratton faithful were starting to grow frustrated with their side’s failure to test Matt Duke in the opposition goal.
Carson was being kept busy, though, and kept out Matty Harriott’s effort from distance on 63 minutes.
Duke was finally called into action moments later, but Racon’s deflected strike did not cause him too many problems.
Padovani then skipped past a couple of challenges inside the opposition area before undoing all his good work by scuffing wide.
The match was suddeny producing chances and Joe Devera should have done better than blaze over after Holmes’ corner found its way to the defender at the far post.
Barker made his first suubsitution on 75 minutes, bringing on Ryan Bird for the tiring Agyemang up front.
But it was the visitors who were next to threaten and Ertl made a brave headed clearance following a mix-up between Carson and Bradley in dealing with a cross.
A scond change soon followed, with Danny East limping off to be replaced by Bondz N’Gala on 79 minutes.
And David Connolly then came on for Ertl in an attacking move as Pompey chased all three points.
But the Blues were unable to find a way through a stubborn back-line and it took a desperate sliding challenge from Bradley late on to deny the Cobblers a shock victory.
Pompey (4-1-4-1): Carson; East (N’Gala 79), Devera, Bradley, Painter; Ertl (c) (Connolly 83); Wallace, Padovani, Racon, Holmes; Agyemang (Bird 75)
Subs not used: Sullivan, Whatmough, Maloney, Harris
Northampton (4-3-2-1): Duke; Amankwaah, Reid (c), Collins, Widdowson; Deegan, Tozer, Harriott; Hackett, Emerton (Demontagnac 83); Norris (Moyo 34)
Subs not used: Heath, Roberts, Heath, Hooper, Toney
Referee: Gavin Ward
Attendance: 15,426 (728 away fans)