Conor Chaplin was the match-winner as Pompey toppled Derby in the Capital One Cup.
The Blues picked up a 2-1 win over the Championship side on a night of cracking football at Fratton Park.
An excellent atmosphere was served up by the crowd of 11,573 as Paul Cook’s side deservedly advanced.
Adam McGurk’s 49th-minute header was cancelled out by Jason Shackell 14 minutes from time.
But then up stepped teenager hitman Chaplin with a poacher’s finish to send the Blues through.
Pompey’s performance in the first 45 minutes saw them continue from where they left off in Saturday’s league win over Dagenham and Redbridge.
Paul Cook’s men forced the Championship side on to the back foot for long periods.
Debut-making Brandon Haunstrup was involved in teeing up McGurk, who pulled his shot wide after 13 minutes.
The lively Kyle Bennett then dragged a shot wide from 20 yards
It took 31 minutes for Derby to threaten as Andreas Weimann’s shot was deflected wide.
Then the busy Haunstrup saw his cross-shot tipped over for a corner by Lee Grant.
Bennett curled a 25 yarder over the top after 36 minutes before Matt Clarke cleared Johnny Russell’s drive across goal off the line.
Jeff Hendrick threatened on the stroke of half-time as he fired wide, but it was a first-half effort Pompey could go in pleased with at the break.
It took four minutes of the restart for Pompey to take the lead through McGurk. It was Jayden Stockley who gave the supply from the right and the Irishman headed through a weak effort to save from keeper Lee Grant.
Stockley and Evans then had shots saved in quick succession as Pompey continued to push, before Bennett’s shot was blocked from a jinking run.
But Derby levelled with 16 minutes left as Jason Shackell was able to rise from a corner and head past Jones.
Sub Chaplin was in dreamland two minutes later though, as he settled an exciting clash with his clinical first-time finish from Enda Stevens’ cross.