Greg Halford rose highest to secure a draw and spare Pompey’s blushes.
The Blues slumped to a 2-0 deficit against a Charleston Battery XI side made up of college kids and fringe players.
That was after some poor defending in the opening 32 minutes.
Zach Kelly’s explosive finish and the impressive Levi Coleman ensured the hosts boasted a two-goal advantage going into the interval.
The 16 travelling Pompey fans given permission by the clubs to enter the behind-closed-doors match feared the worse.
But within 57 seconds of the restart, Sean Flatley threw a lifeline with a calamitous own goal.
Coupled with an improved second-half display, Steve Cotterill’s men stormed right back.
And it was Halford, at fault for the second goal, who sealed the comeback on 75 minutes.
Man-of-the-match Luke Varney swung in a delivery from the right and the Pompey defender rose to plant a header past keeper Andrew Dykstra.
Late on, Ricardo Rocha was fortunate to escape a red card after pulling back JC Mack as the Charleston substitute burst clean through on goal.
As it was, though, the match finished all square for a satisfactory start to the friendly programme in America.
A plus point was also the return of Liam Lawrence following his ongoing calf problem, the fans’ favourite playing the opening 45 minutes.
However, triallist Shavar Thomas did not impress and it appears unlikely that the Jamaican defender will have done enough to win a contract.
Before the match, Cotterill elected to push promising Ryan Williams into a central striking role to partner Dave Kitson up front.
Although having appeared on the wings in his two previous friendly appearances, the young Australian can also operate down the middle.
For Kitson, it was finally a strike partner he craved, having performed on his own up there for the majority of last season.
Elsewhere, Lawrence and Luke Varney occupied the wide positions in a four-man midfield.
There was also a start for triallist Thomas, lining up alongside Halford in the centre of defence.
The Jamaica international is spending the week in Charleston with Cotterill’s men as he bids to win a deal.
Meanwhile, there was no place in the squad for Kanu, whose late arrival for pre-season – coupled with the fact he has a slight back problem – has put him behind the rest of his team-mates.
In the build-up to last night’s game, he had returned to light training only 24 hours previously as Pompey look to ease him back in.
Kanu’s initial presence in the stands certainly pleased the travelling Blues fans who gathered for a quick photograph.
The gloriously-named Seedy Bah had the first sniff of goal when he drove over the bar from inside the box on eight minutes.
At the other end, excellent work from Varney down the left resulted in him pulling the ball back for Williams who shot over the woodwork.
Moments later and Cotterill’s men were unfortunate not to break the deadlock.
On 14 minutes, Tal Ben Haim’s cross from the right was pinpoint and Varney planted a far-post header across goal which agonisingly smacked against the inside of the post.
However, it was Battery who took the lead on 20 minutes.
A cross was swung in from the right and, with Ben Haim outnumbered, Coleman calmly squared for Kelly to spectacularly drive the ball into the top corner.
Barely 12 minutes later and the hosts had doubled their advantage following a lapse from Halford.
Nigel Marples’ ball down the middle saw the Pompey defender the wrong side of Coleman just past the halfway line.
The youngster’s pace kept him ahead of Halford and he calmly clipped the ball over the advancing Jamie Ashdown.
The Blues had a great chance to reduce the deficit on the stroke of half time, yet Varney could only shoot against the legs of Andrew Dykstra following Kitson’s clever pass.
Moments later, Hermann Hreidarsson saw his header from Varney’s left-wing corner palmed around the post by the Charleston shot-stopper.
Pompey made five substitutions after the break and within 57 seconds of the second half, they had cut the deficit.
Ward, one of those players to come off of the bench, galloped down the right and his ball into the box was needlessly crashed home past Dykstra by Sean Flatley.
The visitors had the lifeline they craved and began to exert more meaningful pressure than they did in the first half.
Clearly stepping up a gear, Battery were on the back foot, while the decision to withdraw the impressive Coleman also provided a pep-up.
Pompey were denied an equaliser on 74 minutes when Stephen Armstrong hacked substitute Jason Pearce’s header off the line.
A minute later, though, Halford headed home Varney’s free-kick and it was all square.
Rocha could have been sent off for hauling back Mack in the final few minutes but instead escaped with a yellow card.
Moments later the final whistle sounded to ensure the match finished all square.
Pompey will now be looking for an improved display when they take on Charleston Battery’s first team on Wednesday, July 27.