Paddy Lane headed against the bar in the first half and several chances were also missed, but after the break it was a tough battle for John Mousinho’s men.
However, they dug deep to secure their clean sheet in a goalless draw and, with Bolton and Derby both losing, now lead the table by seven points.
Here are our Pompey player ratings...
1. Will Norris - 7
One sharp second-half save, while gratefully grasped the ball when it ricocheted off the post to him in the opening minutes. Kicking very good and also a figure of calmness. Photo: Jason Brown
2. Joe Rafferty - 7
His 16th-minute cross from the right created chances for Lang and Lane, while a crucial covering clearance on the stroke of half-time prevented a certain Charlton goal. Can never underestimate his importance to team. Photo: Jason Brown
3. Conor Shaughnessy - 8 - MOM
Suffered a facial cut after a clash of heads with team-mate Pack late in the first half which required treatment on a few occasions, but battled on. The pick of the defence - and his team-mates for that matter. Helped Pompey survive a tough second half. Photo: Jason Brown
4. Sean Raggett - 8
Another big performance from the in-form centre-half who is enjoying a fine second half to the campaign. Won everything in the air and dominant on the ground. One late slip up with the ball. Photo: Jason Brown