John Mousinho's men hold a three-point advantage over the Trotters in the race for the third-tier crown, although Monday's visitors have a better goal difference and - perhaps crucially - a game in hand.
Match preview
The disappointment of being knocked out of the FA Cup by Chesterfield has mostly subsided for Portsmouth, who hit a mini-plateau in the wake of that elimination but have reverted to type by clinching back-to-back wins in their last two League One affairs.
Taking to the road twice in quick succession, Mousinho's men were 2-0 victors at Burton Albion on November 28 before going one better on Northampton Town's territory, storming to a 3-0 success last weekend owing to Sean Raggett's header and two Paddy Lane efforts.
Prior to the commencement of this weekend's action, only Reading and Derby County had also taken six points from their last six third-tier matches, but Portsmouth's overall total of 42 sees Mousinho's men sitting pretty at the top of the pile after 19 matches.
Only Bolton are capable of catching Pompey in the current round of fixtures, and the hosts have another incentive to increase their advantage at the summit on Monday evening, having failed to put on much of a show for the home crowd in recent weeks.
Indeed, Portsmouth have gone winless in their last two League One contests at Fratton Park - drawing 2-2 with Charlton Athletic and suffering a horrendous 4-0 humbling versus Blackpool in November - but not since January 2022 have the hosts lost back-to-back third-tier matches on their own soil.
Bolton also have a mistake of their own to rectify on Monday, albeit only a very minor one as their eight-game winless run came to an end in a goalless draw versus Oxford United - a fellow automatic promotion chaser - in their most recent League One contest last month.
Since the opening of advent calendars up and down the country, Bolton have only tested their mettle in cup competitions, although both contests were worthwhile experiences for the Trotters, who ensured progression in both the FA Cup and EFL Trophy.
After pummelling Harrogate Tow 5-1 in the FA Cup second round, setting up a third-round date away to Premier League new boys Luton Town, Bolton's EFL Trophy defence continued with a 2-0 beating of Port Vale on Tuesday, as Dion Charles and Carlos Mendes Gomes made the net bulge.
That routine success marked a 10th win from 11 games for a Bolton side walking in a winter wonderland, and victory at Fratton Park on Monday would send the Trotters above Portsmouth to the summit of the standings, albeit only courtesy of their superior goal difference.
From their 11 unbeaten matches, a defensively-sound Bolton have only let in a mere four goals - keeping clean sheets in each of their last five games in League One - but Portsmouth ran out 3-1 winners in February's Fratton Park fixture and have all the motivation they need to make lightning strike twice against their closest challengers.
Portsmouth League One form:
D
W
D
L
W
W
Portsmouth form (all competitions):
L
W
D
L
W
W
Bolton Wanderers League One form:
W
W
W
W
W
D
Bolton Wanderers form (all competitions):
W
W
W
D
W
W
Advert - content below:
Team News
As well as 18-year-old defender Josh Dockerill - who is on the long road to recovery from a cruciate ligament injury - Portsmouth will be unable to call upon the services of 11-goal top scorer Colby Bishop for the top-of-the-table showdown due to an ankle injury.
Mousinho does not expect Bishop to be out for any longer than a month, but Kusini Yengi should shoulder the attacking burden for the visit of Bolton, where all of Regan Poole (ACL), Anthony Scully (knee), Connor Ogilvie (ankle) and Chelsea loanee Tino Anjorin (hamstring) will be missing too.
On a brighter note, Welsh midfielder Joe Morrell has served his suspension and is at Mousinho's disposal once more; the 26-year-old will likely link arms with Marlon Pack in the engine room.
Meanwhile, Bolton have George Johnston (knee) out for the season, and the Trotters have also lost Dan Nlundulu to the problem that he picked up in the dying embers of his side's EFL Trophy beating of Port Vale.
The visitors are in good shape otherwise, though, and Nlundulu's injury guarantees a two-pronged attack of Charles and Victor Adeboyejo, who lead the way in the Pompey goalscoring charts with 17 between them.
Portsmouth possible starting lineup:
Norris; Rafferty, Shaughnessy, Raggett, Sparkes; Morrell, Pack; Kamara, Saydee, Lane; Yengi
Bolton Wanderers possible starting lineup:
Coleman; Iredale, Forrester, Toal; Morley; Dacres-Cogley, Dempsey, Maghoma, Ashworth; Adeboyejo, Charles
We say: Portsmouth 0-1 Bolton Wanderers
Losing their leading marksman before the visit of a Bolton side who have been near-unbreakable in recent games was not on Portsmouth's bingo card, although their extended recuperation period should at least play its part for the hosts.