Owen Moxon came off the bench to score a fine strike and ensure Pompey collected a deserved point from an entertaining contest with Derby.
A packed – and wet – Fratton Park saw the hosts twice have to battle from behind to maintain their five-point lead at the League One summit.
Joe Ward’s opener was quickly cancelled out by Abu Kamara, only for the Rams winger to restore their lead with a deflected strike.
It looked as though the Blues’ dominance of possession would count for nothing, only for a moment of Moxon magic to rescue them.
John Mousinho made a couple of changes from the side that won on the road at Wycombe on Good Friday.
Lee Evans was handed his first start for the club, while Joe Rafferty also returned, as Moxon and Zak Swanson dropped to the bench.
There was a welcome return to the bench for Tino Anjorin, with the Chelsea loanee having not featured since injuring his hamstring at the start of November.
The atmosphere was electric as the rain swirled around the ground and the hosts were soon on the front foot.
They had an early opportunity when Joe Wildsmith slid out of his box on the slick surface with the ball still in his hands.
A free-kick was awarded and the keeper escaped further punishment, tipping Kamara’s effort over the bar.
And when a corner from Evans was not properly dealt with, Marlon Pack’s follow-up attempt was blocked.
Pompey were looking confident in possession, only to fall behind following a quick Derby break midway through the first half.
Corey Blackett-Taylor surged down the centre of the pitch and laid the ball off for Ward to arrow into the bottom corner.
But the Blues did not let that deflate them and were back on level terms within four minutes of the restart.
Sean Raggett played a pass out to Rafferty on the right and he then found Colby Bishop, whose neat flick picked out KAMARA.
The forward took the ball inside with a fine touch to beat Curtis Nelson before confidently slotting into the net.
It might have got even better when Rafferty collected the ball from Kamara on the overlap, but his delivery was cleared before it could reach Connor Ogilvie.
Instead, the hosts found themselves behind again on 35 minutes, as James Collins played a pass across to Ward, whose shot took a huge deflection off Ogilvie to beat Will Norris.
Half Time: Pompey 1 Derby 2
The hosts continued to control possession once the action restarted and were just trying to find a route through the Rams back-line.
Ogilvie won a corner after Raggett had done well to keep the ball in play, but a dangerous Evans delivery was cleared.
Pompey’s mood was not helped by Wildsmith looking to use up as much time as possible over goal-kicks, with referee Will Finnie electing just to give the keeper a warning.
They were still pushing for an equaliser and Saydee charged into the box from the right, but could not beat Wildsmith from a tight angle, with Bishop screaming for the pass.
Mousinho made a switch just before the hour mark, with Evans coming off to be replaced by Moxon in the engine room.
Two more changes followed on 70 minutes, with Kusini Yengi and Anjorin brought on for Saydee and Paddy Lane.
Derby were happy to soak up pressure and frustrate the Blues, and were doing well to limit their hosts’ chances.
It was going to require something special to get the home side back on level terms – and that is exactly what MOXON provided.
The midfielder collected a pass from Raggett, took a neat touch to beat James Collins and hit an absolute screamer that brushed the fingertips of Wildsmith on its way into the net.
Both sides still sensed a winner was on the cards, but Anjorin had penalty appeals waved away after going down in the box under Korey Smith’s challenge.
Pompey kept pushing in search of a late winner, although they ultimately had to settle for a share of the spoils.
Pompey (4-2-3-1): Norris; Rafferty, Raggett, Shaughnessy, Ogilvie; Evans (Moxon 59), Pack (c); Kamara (Whyte 90+1), Saydee (Yengi 70), Lane (Anjorin 70); Bishop
Goals: Kamara 27, Moxon 77
Booked: Lane, Ogilvie
Subs not used: Macey, Swanson, Sparkes
Derby (4-4-2): Wildsmith; Wilson, Nelson, Cashin, Sibley; Ward (Thompson 71), Adams, Smith (Hourihane 90+2), Blackett-Taylor (Washington 85); Mendez-Laing (c), Collins (Waghorn 90+2)
Goals: Ward 23, 35
Booked: Collins
Subs not used: Vickers, Robinson, Fornah
Referee: Will Finnie
Attendance: 20,129 (2,154 away fans)
