It is a barren spell that was finally broken at the University of Bolton Stadium.
Pompey’s centre-backs had failed to contribute a goal this season, but the pair of them ensured three points would be heading back to the south coast.
Christian Burgess followed up to put the ball in the net after Sean Raggett’s header from a Steve Seddon free-kick had been kept out.
And Kenny Jackett was delighted to see his troops continue their recent resurgence from set-pieces to secure a valuable away win.
The Blues boss said: “It’s a great win. The first half was fairly even, although I thought we looked the slightly stronger side.
“It was great to see us get our noses in front through a set-piece because we had a lot of them and wasted a few good opportunities.
"It was great to see us get our noses in front through a set-piece because we had a lot of them and wasted a few good opportunities."
“In the end, though, it was Seddon’s delivery and Raggett got the first touch, with Christian doing well to follow up.
“My centre-backs haven’t contributed enough in the other box this season and if you need that if you want a successful season.
“Bolton were right on top of us just after the break and the changes we made helped to protect our midfield.
“Andy Cannon played very well when he came on and really did make a difference, although we were looking for that second goal on the break.
“That didn’t come, but I have to congratulate the players because they fought for each other and showed fantastic spirit to get over the line.
“I also have to thank our fans, who travelled a long way to support us. They really contributed and we appreciate their efforts.”
Home supporters thought Raggett should have been dismissed for a challenge on Joe Dodoo while the game was goalless.
Jackett said: “It was touch and go about whether James Bolton would have made it or whether the keeper would have come out.
“Their the decisions that the referee has to make because it’s not an automatic red card if there’s a covering man.”