There was a flurry of chances for Pompey to claim all three points late in the game.
But they ultimately had to settle for a goalless draw with Shrewsbury in their League One opener at Fratton Park.
Tom Naylor saw a header rattle the crossbar, while Lee Brown went close with a couple of free-kicks and headers from Sean Raggett and Ryan Williams were diverted to safety by Scott Golbourne blocks.
The visitors did not have quite as many opportunities, but those they did create were certainly good ones.
And while Kenny Jackett was pleased to prevent them finding the net, he conceded that his side lacked a spark.
The Blues boss said: “We built up a good head of steam in the second half and had some chances, but couldn’t quite find that final ball or finish.
“It was our second clean sheet in a week and that’s a positive, although our opponents had two chances from corners.
"We were just looking for that little bit more quality during that period when we did get going."
“One of them hit the post and from the other my keeper made a top save, but we struggled to deal with their power from set-pieces. We coped well from open play, though.
“Their keeper has made some good saves as well, while we also hit the woodwork and Lee was very unlucky from a free-kick.
“We were just looking for that little bit more quality during that period when we did get going and looked like making a breakthrough.
“The positives are that we’re unbeaten now from three games in three different competitions, but of course we want to build on that.”
Aaron Pierre was dismissed Shrewsbury in stoppage-time, collecting his second booking for a foul on John Marquis.
But Jackett felt his earlier challenge on the striker just outside of the area perhaps warranted a straight red card, instead of the yellow one that was brandished.
He said: “I thought it was a sending off and if you’re the defender in that situation, you’re not surprised if the referee gets out a red card.”