Pompey became the 12th League One side to draw at Lincoln this season in a game that only really got going in the closing stages.
There were opportunities for both teams, but it was a mostly quiet afternoon for the men between the sticks.
Danny Mandroiu did strike the bar for the Imps, while a late chance for Colby Bishop was lifted over the bar before each keeper came to the rescue at the death.
John Mousinho made two changes from the side that dramatically beat Burton on home soil earlier in the week.
Matt Macey recovered from illness to replace Josh Oluwayemi in goal, while Louis Thompson made way for Ryan Tunnicliffe in midfield.
Di’Shon Bernard and Ronan Curtis were both considered fit enough for a spot on the bench, but Marlon Pack was still sidelined.
The first half contained plenty of promising moments for both sides, but there was not a single shot on target.
Lincoln might have taken the lead when a ball over the top send Jack Diamond racing clear, only to fire wide with just Macey to beat.
The forward was looking an early threat for the home side and dragged an angled shot narrowly past the post.
But Paddy Lane then sent the ball into the mixer and although Regan Poole nodded it clear, Tunnicliffe fired the loose ball just off target.
Joe Morrell then surged through the middle of the pitch and laid the ball off for Joe Rafferty, whose teasing cross was just out of reach for Reeco Hackett in the box.
He did well on 34 minutes, however, collecting a fine cross-field Tunnicliffe pass, cutting onto his left foot and drilling the ball inches wide.
It was the Imps who finished the half strongly, however, and Luke Plange was not quite able to keep his shot on target.
A series of corners then caused a few nerves in the Blues box, but it all ended with Ethan Erhahon blazing high over the bar.
Half Time: Lincoln 0 Pompey 0
The visitors threatened shortly after the restart and Poole threw himself in front of Lane’s shot to divert the ball over.
But there was not much else happening in a slow start to the second half, with both sides struggling to find any rhythm.
That almost changed around the hour mark, with each of them coming close to breaking the deadlock.
Mandroiu did well to turn on the edge of the box and fire in a shot that came back off the bar, with Mide Shodipo firing the loose ball wastefully over.
Mousinho responded with a double substitution, as Owen Dale and Lane made way for Joe Pigott and Ronan Curtis.
And the latter almost made an instant impact, meeting Rafferty’s teasing low delivery at the back post and seeing his shot diverted wide by a lunging Poole.
Another switch followed for the visitors on 73 minutes, with Tuesday night’s match-winner Dane Scarlett replacing Hackett.
Lincoln were left cursing the officials when substitute Lasse Sørensen was denied a penalty after going down under a Curtis challenge.
But the boot was quickly on the other foot, as Scarlett was denied by an offside flag when he found the back of the net.
Bernard came on for Rafferty and a poor pass saw the Imps break quickly up the pitch, but the defender recovered to clear Diamond’s ball into the box.
Bishop finally called Carl Rushworth into action at the other end, although it was a regulation save for the keeper.
But Bishop should have done better moments later when Pigott flicked on Connor Ogilvie’s pass and he was through on goal, only to lift the ball over the bar.
Lincoln then might have snatched victory at the death, but Macey – who had not previously had much to do – got down to his right to deal with Charles Vernam’s low drive.
The game had suddenly burst into life and Rushworth denied Curtis from point-blank range before the action switched and Macey kept out Vernam’s effort to ensure it finished all square.
Lincoln (3-4-3): Rushworth; Eyoma, Jackson (Mandroiu 21), O’Connor; Poole (c), Bishop (Sørensen 72), Erhahon, Roughan (Boyes 76); Diamond, Plange (Vernam 72), Shodipo
Booked: Mandroiu, Eyoma
Sub not used: Wright
Pompey (4-3-3): Macey; Rafferty (Bernard 82), Raggett (c), Towler, Ogilvie; Lane (Curtis 59), Morrell, Tunnicliffe; Dale (Pigott 59), Bishop, Hackett (Scarlett 73)
Booked: Morrell, Rafferty, Hackett, Pigott
Subs not used: Oluwayemi, Thompson, Jacobs
Referee: Ross Joyce
Attendance: 9,906 (1,313 Pompey fans)