Ronan Curtis scored on the stroke of half-time to fire Pompey to victory in an otherwise uneventful match at Coventry.
Not that the near-2,000 travelling fans will care much about the quality of the contest, as they saw their side extend their unbeaten start to the season.
In a game of extremely few genuine opportunities, Curtis’ curling finish stood out and ensured the Blues remained top of the League One table.
Kenny Jackett unsurprisingly stuck with the same side that beat Rochdale to reach the League One summit on Saturday.
There were a few familiar faces in the opposition line-up, with Michael Doyle, Tom Davies and Dom Hyam all starting, and Liam O’Brien on the bench.
The first half was a largely forgettable affair, with long periods of lifeless play punctuated by a few key moments.
Pompey were first to threaten and Ben Close should at least have sent the ball on target when he met Nathan Thompson’s cross with a side-foot shot.
A dangerous corner from Gareth Evans then had to be headed clear by Jonson Clarke-Harris, as the visitors looked to make a fast start.
But there were not many other clear-cut opportunities to excite the crowd inside the cavernous Ricoh Arena.
A booking apiece for Dujon Sterling and Tom Naylor rose them from their slumber, although the latter was adamant he had won the ball cleanly from Luke Thomas.
But Pompey received a let-off on the half-hour mark when Matt Clarke inexplicably stopped in his tracks, allowing Clarke-Harris to surge towards goal.
Craig MacGillivray thankfully came to the rescue, tearing from his line to make a vital save and then leaping on the loose ball.
It looked like the sides would crawl uneventfully towards the interval, with a few Blues crosses that were headed clear about as exciting as it got.
But the large travelling army from the south coast had reason for their non-stop chanting in stoppage-time.
Evans stole possession from former team-mate Doyle and Close’s pass was nodded down by Brett Pitman.
It looked like CURTIS had taken too long to get his shot away, but he was merely making space to curl home a fine finish.
Coventry City 0
Pompey made an energetic start to the second half, although Evans was forced to take one for the team and pick up a booking when Thomas broke quickly following a corner.
But it was still proving to be a fairly scrappy encounter, with both sides struggling to keep hold of the ball.
There were plenty of bs being sent into the boxes, but it always seemed to be an opposition player getting on the end of them.
Coventry did enjoy more possession as the half progressed, although it was proving a comfortable evening for MacGillivray.
Tony Andreu attempted an ambitious volley on the edge of the Blues box and swiped at thin air to sum up the attacking quality on display.
Jackett made a chance on 70 minutes, bringing on Ben Thompson to replace Close and shore up his midfield.
And Pitman then made way for Oli Hawkins as time continued to tick away without anyone looking likely to add to the scoring.
The first of those newcomers did have a rare chance towards the end, with a fierce finish that Lee Burge just about dealt with.
Jamal Lowe also curled a shot narrowly past the post, as Pompey appeared to be comfortably heading for victory.
But they survived a scare at the death, with MacGillivray failing to hold Doyle’s free-kick and a scramble ensuing before Naylor hooked from the line.
Coventry (4-2-3-1): Burge; Willis, Davis, Hyam (Thompson 46), Sterling; Bayliss, Doyle (c); Thomas, Andreu (Hiwula 73), Shipley (Jones 56); Clarke-Harris
Subs not used: O’Brien, Kelly, Ogogo, Bakayoko
Pompey (4-2-3-1): MacGillivray; N.Thompson, Whatmough, Clarke, Brown; Close (B.Thompson 70), Naylor; Lowe, Evans, Curtis; Pitman (c) (Hawkins 83)
Goals: Curtis 45+2
Booked: Naylor, Evans, N.Thompson
Subs not used: McGee, Walkes, Haunstrup, Wheeler, Mason
Referee: Brett Huxtable
Attendance: 11,102 (1,961 Pompey fans)