Craig MacGillivray was the penalty hero for Pompey, as they fought from behind to win at Stevenage and reach the second round of the Carabao Cup.
Elliot List and Charlie Carter took advantage of some extremely sloppy defending to give Stevenage a commanding lead in the opening 10 minutes.
Ronan Curtis reduced the deficit, but again Pompey were their own worst enemy to allow Scott Cuthbert to score.
But Gareth Evans converted from the spot on the stroke of half-time and, in a much-improved display following the interval, John Marquis emphatically levelled.
The tie went to a penalty shoot-out and substitute MacGillivray saved three of the hosts’ four efforts to ensure the Blues progressed.
Kenny Jackett named a strong squad for the opening game of the 2020/21 campaign, with skipper Tom Naylor returning to the side following his play-off absence.
There was room on the bench for a couple of talented youngsters, though, with teenagers Haji Mnoga and Alfie Stanley both included.
The players and coaching staff from both sides – as well as the officials – all took the knee before kick-off in a show of support for the fight against racism.
It did not feel like August at an eerily quiet Broadhall Way, with the rain falling and temperature unseasonably low.
And Pompey were certainly caught cold in the opening stages, with two pieces of dreadful defending gifting their opponents goals.
Sean Raggett was caught out by a Luke Prosser pass on nine minutes, allowing a gleeful List to nip in and slot home.
And it got worse just a few seconds later following a dreadful mix-up between Paul Downing and Alex Bass.
But there were still several chances for the visitors to get the ball clear before it ricocheted into the path of Carter to score.
Pompey almost grabbed an immediate lifeline when Evans delivered a cross from the right, only for Jamie Cumming to make two fine saves in quick succession to deny Marquis and Curtis.
But the deficit was reduced midway through the first half, as Raggett and Lee Brown combined well down the left.
The latter slipped a pass across to CURTIS, who cut onto his right foot and curled a precise shot into the net.
With the ground closed for supporters from both sides, there was still the familiar sound of a cowbell outside the ground.
Even that was failing to lift the Blues, though, who continued to lack much cohesion in their forward play.
And they were still looking nervy at the back, with another defensive error restoring Boro’s two-goal advantage.
Bass punched a corner straight up into the air and an almighty scramble followed before the ball landed for Cuthbert to poke over the line.
Pompey tried to fight back and Raggett was at least showing desire, with a crunching – yet fair – challenge on List.
Evans perhaps showed a bit too much just before the break, though, and his foul on Carter was punished with a yellow card.
But the same player pulled one back for the Blues from the penalty spot right at the end of the first half.
Ben Coker was punished for handling Marquis’ shot in the box following some tricky play from Marcus Harness.
It was the reliable EVANS who was entrusted with converting from 12 yards and he calmly sent Cumming the wrong way.
Half Time: Stevenage 3 Pompey 2
There was probably no surprise that Jackett decided to make a change at the back during the break and it was Bass who was withdrawn for MacGillivray.
His first piece of action was to watch on nervously as Carter’s effort was dragged narrowly past the post.
But the Blues were a lot brighter and they found themselves impressively back on level terms on 51 minutes.
Curtis delivered a first-time pass to MARQUIS, who raced onto the ball and hit a rocket of a shot into the top corner of the net.
Pompey looked like a different team, as they started to dictate the tempo of the game and get forward down the left.
And when Harness collected Evans’ pass and lifted a cross into the area, Curtis met the ball with a volley that was well saved by the busy Cumming.
Bryn Morris was unable to test the keeper soon after, blazing high over the bar after an initial Curtis effort was blocked.
Jackett brought on some fresh attacking legs on 76 minutes, with Andy Cannon and Ryan Williams replacing Evans and Harness.
And when Cannon was brought down on the edge of the box, it almost led to the Blues taking the lead for the first time.
Brown played a clever free-kick through to Curtis, whose angled drive was pushed against the post by Cumming.
Penalties were looming, but Danny Newton came close to a stoppage-time winner for the hosts, bursting into the box and forcing MacGillivray into action at the keeper’s near post.
Full Time: Stevenage 3 Pompey 3
Both sides scored their first penalties, with Inih Effiong on target for Stevenage and Marquis quickly levelling.
But then MacGillivray took control and made three fine saves to deny Newton, Elliot Osborne and Coker.
The last of those sealed a 3-1 shoot-out triumph after Curtis and Brown had both converted their spot-kicks in style.
Stevenage (4-3-3): Cumming; James-Wildin, Cuthbert (c), Prosser, Coker; Osborne, Vincelot (Newton 64), Carter; List (Hutton 79), Effiong, Marsh (Akinwande 53)
Goals: List 9, Carter 10, Cuthbert 29
Subs not used: Johnson, Smith, Marshall, Dinanga
Pompey (4-3-3): Bass (MacGillivray 46); Bolton, Downing, Raggett, Brown; Evans (Cannon 76), Naylor (c), Morris; Harness (Williams 76), Marquis, Curtis
Goals: Curtis 21, Evans (pen) 45+2, Marquis 51
Subs not used: Mnoga, Whatmough, Close, Stanley
Referee: Sam Purkiss