Pompey shared the spoils with Bolton in a tense and absorbing contest at the Toughsteet Community Stadium.
The visitors knew victory would be enough to get the job done – and it was on the cards when Abu Kamara fired them into an early lead.
But Wanderers hit back to level before the break through Aaron Collins and neither side was able to find a winner.
John Mousinho made two changes from the side that beat Shrewsbury on home soil the previous weekend.
A fit-again Callum Lang came straight back into the team after missing the past five games with an ankle injury.
There was also a start for Joe Rafferty at right-back, with Kusini Yengi and Zak Swanson the men to make way.
The sides emerged to a raucous atmosphere, with both sets of fans playing their part, and it was the visitors who made the faster start.
Kamara burst past Nathanael Ogbeta down the right and cut the ball back for an unmarked Lang, whose effort was blocked by Ricardo Almeida Santos.
And the deadlock was broken moments later after KAMARA had stolen possession from Ogbeta halfway up the pitch.
He surged forward before cutting onto his left foot and hit a neat shot inside the near post of Nathan Baxter.
But the Blues were unable to build on that moment of magic and were soon being put under pressure by their hosts.
An equaliser might have arrived when Gethin Jones sent in a low delivery that ricocheted against the post.
A follow-up attempt from Eoin Toal was then blocked by Sean Raggett, while there was more pinball before the danger passed.
Wanderers were enjoying the territorial advantage, but were too often being let down by a wayward final ball.
There was a big opportunity when Jón Daði Böðvarsson broke clear on 32 minutes, but his cut-back flew behind Collins in the box.
It was only a brief reprieve, though, as after a spell of sustained pressure, a stretching Collins was able to head home Ogbeta’s cross.
Pompey looked to hit back and Lang was denied by a good Santos challenge before Paddy Lane saw his attempt blocked.
It was the home side who almost took the lead just before the break, however, with Will Norris getting down to parry away Collins’ drive and Böðvarsson was unable to convert the loose ball.
Half Time: Bolton 1 Pompey 1
There was a change for the visitors at the break, with Chelsea loanee Tino Anjorin brought on for Owen Moxon.
But Bolton had the first chance after the restart, as Josh Sheehan worked his way into a shooting position, only to hit a tame effort straight into the arms of Norris.
George Thomason also drilled an effort wide, while the midfielder was then eased off the ball by Anjorin after breaking into the box.
Mousinho responded with a triple substitution just past the hour mark, as Lang, Lane and Colby Bishop made way for Christian Saydee, Gavin Whyte and Yengi.
The contest turned a bit scrappy, which was perhaps not surprising with so much at stake for both sides.
Saydee looked to slip a pass through to Yengi on 68 minutes, with Santos sliding across to make a key interception.
Wanderers immediately went close at the other end, as Josh Dacres-Cogley did well to keep the ball in play and cut it back for Böðvarsson to fire over from a few yards out.
It was then Pompey’s turn to launch an attack and Yengi found Kamara, whose drilled effort flew inches past the post.
The chances were flowing now and after finding space to exploit, Anjorin hit a fierce strike not too far wide.
Substitutions for the home side halted the flow for a while, but they began to show more urgency as the minutes ticked down.
There were a couple of corners met by Santos, with one turned over and the other finding the safe hands of Norris.
A low Kyle Dempsey centre was then turned against the base of the post by Dion Charles, with the travelling fans at the other end of the pitch breathing a sigh of relief.
Pompey thought they should have been awarded a stoppage-time penalty with Yengi appearing to have his shirt tugged, but referee Anthony Backhouse disagreed.
That proved to be the end of the action, as thoughts now turn to a big Fratton clash with Barnsley on Tuesday night.
Bolton (3-1-4-2): Baxter; Jones, Santos, Toal; Sheehan (Morley 76); Dacres-Cogley, Maghoma (Dempsey 76), Thomason, Ogbeta (Williams 90+2); Collins (Charles 80), Böðvarsson (Jerome 80)
Goals: Collins 36
Booked: Toal, Santos, Jerome
Subs not used: Coleman, Iredale
Pompey (4-2-3-1): Norris; Rafferty, Raggett, Shaughnessy, Ogilvie; Pack (c), Moxon (Anjorin 46); Kamara, Lang (Saydee 58), Lane (Whyte 58); Bishop (Yengi 58)
Goals: Kamara 7
Booked: Lang
Subs not used: Macey, Sparkes, Evans
Referee: Anthony Backhouse
Attendance: 25,738 (2,665 Pompey fans)
