Pompey end 2017 in the League One play-off positions after coming from behind to defeat Northampton Town 3-1 at Fratton Park.
Chris Long opened the scoring for the Cobblers but a fine Matty Kennedy strike and a double from Oli Hawkins delivered Kenny Jackett's troops the three points.
However, a suspected serious leg injury to Danny Rose and Gareth Evans being forced off late in the first half took the gloss off an impressive Blues win.
Hawkins had a golden opportunity to open the deadlock with the first chance of the game in the sixth minute when he was slipped through by Brett Pitman, but the striker’s effort was blocked by the boot of Northampton goalkeeper Matt Ingram.
After a fairly uneventful first half, the game burst into life on 36 minutes when the Cobblers took the lead.
Ben Close was caught in possession and the visitors launched a counter-attack, culminating in Long steering a right-footed effort past Luke McGee.
But the Blues were back on level terms just five minutes later when Kennedy crashed an angled right-footed effort beyond the reach of Ingram.
And Jackett’s troops found themselves ahead through a stunning Hawkins header minutes later.
The former Dagenham & Redbridge talent rose to power home Christian Burgess’ long-range cross over the Northampton shot-stopper and into the far corner of the net.
And Hawkins notched his second of the game four minutes after the restart.
Dion Donohue’s whipped cross picked out the striker, whose eyes were only on the ball and headed home from close range.
Pompey were rampant from that point, with traffic only flowing one way.
Close crashed a shot against the crossbar on 50 minutes, while Hawkins almost had a hat-trick when his header from Kennedy’s free-kick was kept out by Ingram seven minutes later.
And Jamal Lowe should have scored when he steered a gilt-edged opportunity wide of the far post in the 61st minute.
The victory was the Blues' fifth straight success at Fratton Park and their 20th in total this year.
And with Peterborough losing at MK Dons, it meant Jackett's troops moved into the top six for the first time this season.