Conor Chaplin’s superb 89th-minute strike rescued a point for Pompey at Barnet.
The substitute’s right-footed 25-yarder ensured it finished 1-1 at The Hive.
That was after Mauro Vilhete’s free-kick eight minutes from time looked to have given Kevin Nugent’s side the points in his first game in charge.
They were two moments of class which lit up a game low on quality as Pompey’s 2,430 travelling fans outnumbered the home following.
It was a first 45 minutes short on decent play with it taking 25 minutes for a half-decent chance to arrive.
That came as Eoin Doyle flashed a header wide from Gary Roberts’ cross.
Seconds later Curtis Weston shot was punched away by David Forde.
Former Pompey striker John Akinde was Barnet’s key threat and dipped a half volley just over after 28 minutes.
Eoin Doyle then couldn’t quite get a touch on Christian Burgess’ header from Kyle Bennett’s 36th-minute free-kick.
Charlie Clough’s header was deflected wide five minutes before the break in the last action of a poor half.
Pompey made a brave double change at the interval as Chaplin and Danny Rose came on and Cook switched to a diamond and two strikers.
The move failed to see the visitors carve out any chances of note, however before Vilhete’s free-kick.
Forde could do little as he curled his effort over the wall after Matt Clarke fouled Justin Amaluzor.
But then Chaplin stepped up with a bolt from blue in the dying minutes as he blitzed home a 25-yarder.
The result keeps Pompey fifth in the table.