Pompey had to settle for another Fratton stalemate after being unable to break down Derby in an entertaining Friday night fixture.
Both sides enjoyed moments of dominance in a contest that ebbed and flowed, although neither keeper had too much to do.
Danny Cowley made one change from the side that were held to a draw at Morecambe the previous week.
It came in the centre of midfield, where Ryan Tunnicliffe dropped to the bench to make way for Jay Mingi.
There was welcome news on the bench, however, with Ronan Curtis included after recovering from an ankle problem.
A packed Fratton Park create a lively atmosphere once the action started and the first half was an intriguing affair, played at a high tempo.
Owen Dale caused Louie Sibley plenty of problems down the right and one of his crosses was nodded down by Connor Ogilvie, but Max Bird managed to scramble clear.
The visitors went closer to breaking the deadlock soon after, as David McGoldrick turned sharply and fired a shot against the crossbar.
Dane Scarlett then fancied his chances when Jay Mingi was chopped down on the edge of the box, but his low free-kick could not slip under the wall.
Pompey grew stronger as the half progressed and another teasing Dale delivery was sent onto the roof of the net by a looping Ogilvie header.
An angled Dale effort was then parried out by Joe Wildsmith, with the ball flying agonisingly away from the lurking Colby Bishop.
There were another couple of half-chances for Scarlett, as the Blues began to take control of the contest.
But the Rams almost snatched a goal just before the break, with Craig Forsyth not able to turn home Conor Hourihane’s free-kick at the back post.
Half Time: Pompey 0 Derby 0
Koroma had a shot soon after the restart that was curling wide and Dale did brilliantly to keep the ball in play, forcing Derby to scramble it behind.
Clark Robertson could not get enough height on the resulting corner, but Bishop met it with a flick that flew over.
At the other end, a sliding Mingi did brilliantly to get himself in the way of a Liam Thompson effort and divert the ball behind.
The danger was not over, though, and Scarlett cleared Sibley’s shot off the line, with Marlon Pack then nodding over his own bar.
Cowley made a change just past the hour mark, with the fit-again Curtis replacing Koroma wide on the left.
The noise from the stands grew louder as Pompey began to apply pressure on their opponents and were just looking for an opening.
Curtis and Dale were both looking lively and the latter saw a shot blocked in the search for an opening goal.
Derby weathered that storm, though, and Cowley tried to liven things up by bringing on Joe Pigott for Scarlett.
The Fratton faithful tried to roar their side on to find a last-gasp winner, but the deadlock remained unbroken.
Pompey (4-4-2): Griffiths; Swanson, Raggett, Robertson (c), Ogilvie; Dale, Pack, Mingi, Koroma (Curtis 61); Scarlett (Pigott 86), Bishop
Booked: Robertson, Bishop
Subs not used: Oluwayemi, Morrison, Hume, Tunnicliffe, Hackett
Derby (3-5-2): Wildsmith; Rooney (Stearman 78), Forsyth, Cashin; Smith, Thompson (Barkhuizen 78), Bird (c), Hourihane, Sibley; McGoldrick (Osula 87), Collins (Dobbin 78)
Booked: Sibley, Cashin, Thompson, Dobbin
Subs not used: Loach, Oduroh, Aghatise
Referee: Ben Speedie
Attendance: 18,623 (1,270 away fans)