The play-off contest is delicately poised after a 1-1 draw at an eerily quiet Fratton Park.
But Kenny Jackett was pleased with a lot of what he saw from his Pompey troops in their first leg against Oxford.
Ronan Curtis drilled in the opener during the first half, only for Marcus Browne to level before the break.
The hosts looked threatening for spells of the unseasonably blustery contest and Jackett hopes to see more of the same when they travel to the Kassam Stadium on Monday.
The Blues boss said: “We looked pretty strong and I felt we both started and ended the game well, with a lot of decent balls sent into good areas.
“Some didn’t break for us, some were defended well and there were other times when the decisions didn’t go our way.
“If we can keep knocking on the door like that in the second leg on Monday then we’ll be pretty pleased.
"I felt we both started and ended the game well, with a lot of decent balls sent into good areas."
“We’re disappointed with the goal we conceded because Oxford didn’t have that many efforts, while we got into very good positions.
“There were long spells when we were in charge. We asked questions of them and it’s important that we can replicate that.”
Pompey went into the game with no injury worries and despite playing competitive football for the first time in 115 days, everyone came through unscathed.
Jackett said: “We have a fully-fit squad and that’s testament to the staff we've got at this club – it’s something we were aiming for.
“Oxford are a very good side and so it’s important to have everyone available and in peak condition. Hopefully that depth can help us.”
The hosts were visibly frustrated that referee Gavin Ward turned down penalty appeals from Christian Burgess and Curtis.
Jackett said: “My players feel aggrieved, but I haven’t seen the incidents again and don’t want to focus on that too much because the decisions were made and you can’t change them.”