Jake Jervis earned Pompey a precious survival point on his return to league leaders Tranmere.
Jervis’ 75th-minute strike ensured the Blues grabbed a 2-2 draw at the side he was on loan at last month.
That was after Gabor Gyepes’ 49th-minute header had cancelled out Ash Taylor’s first-half opener.
Jervis’ strike arrived at the end of a quick-fire period of second-half goals after Michael O’Halloran had put the home side in front in the 74th minute.
It was a gutsy point from the Blues and answered any questions about their resolve and desire to stay afloat in the division this season.
Pompey may have been facing a daunting trip to the top-of-the-table side, but it was they who looked like the outfit flying high in the game’s opening exchanges.
The visitors were the quicker to settle and didn’t let a bumpy and slippery Prenton Park surface deter them from playing a high-tempo passing game.
A Mustapha Dumbuya angled cross nearly found Paul Benson early on before Rovers keeper Owain Fon Williams gathered.
Nathaniel Mendez-Laing then summed up the hunger Pompey were showing when he stole the ball from defender Ash Taylor.
He looked like he would get clear from that, before Danny Holmes recovered to steal the ball back for Ronnie Moore’s men.
Johnny Ertl was the next to try his luck - smashing a speculative 30 yarder high and wide.
It took 21 minutes for Tranmere to muster an opportunity as Simon Eastwood, being handed his chance in goal, smartly turned Adam McGurt’s daisy-cutter around the post.
Pompey then had Ricardo Rocha to thank for saving a certain goal as he heroically blocked Liam Palmer’s goalbound drive.
Eastwood made a stop any keeper in the world would have been proud of after 28 minutes, when he superbly tipped Andy Robinson’s curler from just inside the box over his upright at full stretch.
Pompey had lost their way after dominating early on and Danny Harrison served notice of intent from Ronnie Moore’s as he thrashed another effort over from 18 yards.
The visitors didn’t heed the warning, however, and fell behind moments later when Adam McGurk’s cross was headed past the helpless Eastwood by Taylor.
It was one-way traffic now and Zoumana Bakayogo’s trickery nearly paid off as he played keepie-uppie in the box before stinging Eastwood’s palms with a volley.
That was the last major opportunity before the break as Pompey were left to ponder how they had let a promising start ebb into a dominant Tranmere display.
The question for caretaker boss Guy Whittingham and Andy Awford now had to be; was there the leadership in the Pompey side to allow them to settle and get a foothold in the game?
The Blues did more than that, though, as they levelled four minutes after the break.
Robinson was the man penalised for a foul on Darel Russell wide right 25 yards out.
That allowed Howard to whip in a pinpoint set-piece which the returning Gabor Gyepes rose high to head past Fon Williams
That sent the 750 or so Pompey fans wild as Gyepes celebrated in front of them - and saw the confidence flowing back into their side.
The match had now become an end-to-end affair with both teams showing intent to win the game.
Jervis was hoping to be the man to do that when he replaced Mendez-Laing midway through the half.
The intensity looked to be drifting out of the game until a crazy period with two goals moments apart.
First, it was the home side who grabbed a second in the 74th minute when Robinson’s cross was turned in from a couple of yards from O’Halloran.
But it took Whittingham’s side seconds to level when Jervis found space to unleash a wonderful angled finish past Fon Williams.
That was the key moment of the game’s finale - although Eastwood had to provide a top late stop to ensure a share of the spoils when Liam Palmer went clear.
And sub Scott Allan could have won it with the last kick of the game as he bundled through and fired agonisingly wide.
That failed to take the shine off the result though as Pompey players and fans saluted each other on the final whistle.
TRANMERE ROVERS 2 (Taylor 31, O’Halloran 74)
POMPEY 2 (Gyepes 50, Jervis 75)
Tranmere: Williams, Holmes, Taylor, Goodison, Palmer, Cassidy, Robinson, McGurk, Harrison, Bakayogo, O’Halloran. Subs: Black, Thompson, Stockton, Power, Kay, Daniels, Mooney.
Pompey: Eastwood, Dumbuya, Gyepes, Rocha, Harley, Russell, Ertl, Howard, Mendez-Laing, McLeod, Benson. Subs: Smith, Michalik, Webster, Compton, Williamson, Allan, Jervis.
Referee: David Webb (Lancashire)