Pompey scored two goals in as many minutes to battle from behind and secure an unlikely draw against Plymouth at Fratton Park.
They dominated the first half, but could not make the most of their territorial advantage and it looked as though the Blues would be made to pay.
Luke Jephcott took advantage of some sloppy play to fire the visitors ahead and then doubled their lead following a quick break.
But substitute Ronan Curtis pulled one back late on and James Bolton found the net just seconds later to ensure the spoils would be shared.
Kenny Jackett made one change from the side were so impressive in victory at Charlton earlier in the week.
Marcus Harness – who came off the bench to provide an assist at The Valley – replaced Ryan Williams, who dropped to the bench.
There was a minute’s applause before kick-off to pay tribute to national hero Captain Sir Tom Moore, as well as former Pompey boss John Mortimore and forward Ron Rafferty.
After making a bright start, the visitors were on the back foot for pretty much the entirety of the first half.
The Blues were looking to apply plenty of pressure, but the ball would not quite land for them in the final third.
They were almost gifted a goal on 20 minutes, though, when Panutche Camara played a loose pass straight to Harness.
The winger got away a clean strike, but Michael Cooper was able to get down to turn the ball around the post.
That led to a series of five corners in quick succession that Argyle struggled to deal with, particularly the first.
Skipper Tom Naylor attacked the delivery from Michael Jacobs and the ball was heading for the net, but Kell Watts was able to clear from the line.
Cooper was looking nervy with the ball at his feet and was almost charged down by John Marquis on one occasion, while a later pass came close to being intercepted by Ellis Harrison.
And the keeper then struggled to deal with a fierce Harrison effort that was straight at him, fumbling it behind for yet another corner.
He did better just before the break, however, getting down to deal with a skidding long-range Harrison strike.
Half Time: Pompey 0 Plymouth 0
The hosts continued where they left off once the action restarted by winning a couple more early corners.
But it was a relatively flat opening to the second half, with plenty of scrappy play and little attacking inspiration at either end of the pitch.
Plymouth had a chance with a corner of their own just before the hour mark, but an unmarked Will Aimson could only nod Danny Mayor’s cross straight at Craig MacGillivray.
Jackett was then forced to make his first change of the afternoon, as Jacobs limped off to be replaced by Curtis.
There was a moment of concern when Jephcott cut the ball back for Ryan Hardie, only for Sean Raggett to make a perfectly-timed sliding challenge inside the box.
But Pompey were soon on the attack themselves and there was an almighty scramble, with white-shirted players throwing themselves in the path of shot.
The action quickly switched up the other end of the pitch, with the ball pinging around before Jephcott’s effort was deflected behind.
Harvey White was brought on for Harrison on 69 minutes, as the Blues searched for some fresh impetus.
But Argyle broke the deadlock soon after, with Camara stealing the ball from Andy Cannon and receiving a pass back from Niall Ennis.
Three players dived in on the midfielder, who calmly teed-up Jephcott to poke home. The scorer immediately looked across to the linesman, whose flag stayed down.
Pompey tried to hit back and there was controversy when Charlie Daniels’ shot appeared to strike the arm of Aimson.
But referee Will Finnie waved away penalty appeals and Plymouth went straight up the other end to double their lead, with Ennis squaring for Jephcott to convert.
It looked like game over for the hosts, but they kept their heads high to launch an incredible fightback.
They reduced their deficit when CURTIS stole the ball from Watts, cut onto his left foot and impressively found the net from a tight angle.
And, just seconds later, Harness swung in a fine cross that was attacked by the heads of both Raggett and Bolton.
It was difficult to see who got the final touch, but BOLTON wheeled away to celebrate and Pompey suddenly sensed they could claim all three points.
Their hopes were raised by a display of five additional minutes, but Plymouth held on to at least take something back with them to Devon.
Pompey (4-4-2): MacGillivray; Johnson, Bolton, Raggett, Daniels; Harness, Naylor (c), Cannon, Jacobs (Curtis 60); Marquis, Harrison (White 69)
Goals: Curtis 86, Bolton 87
Booked: Cannon, Naylor
Subs not used: Ward, Mnoga, Brown, Byers, Williams
Plymouth (3-5-2): Cooper; Aimson, Opoku, Watts; Moore, Camara (Lewis 90), Fornah, Mayor (c), Grant; Hardie (Ennis 69), Jephcott (Woods 84)
Goals: Jephcott 71, 82
Subs not used: McCormick, Law, Reeves, Lolos
Referee: Will Finnie