Kenny Jackett has often underlined the importance of set-pieces for Pompey.
So he was frustrated to see his side undone by a corner in their 2-1 defeat to Sunderland at the Stadium of Light.
The visitors controlled long periods of the latest clash between the sides and led through Marcus Harness’ first goal for the club.
But Jordan Willis soon nodded home a flag-kick to level, while former Fratton loanee Chris Maguire hit what turned out to be the Black Cats winner before the break.
Jackett’s men had opportunities to leave with at least a point, although he felt they could have done more to test keeper Jon McLaughlin.
The Blues boss said: “It was frustrating because we started well and were on top in both halves, getting the important first goal.
“But then we conceded from a corner and that brought the crowd into play. Those set-pieces are so vital and it was poor from our point of view.
"It was frustrating because we started well and were on top in both halves."
“The second one was a quality goal after picking up a second ball – they have those flashes from the likes of McGeady, McNulty and Maguire.
“But they were the only real two shots they had in the game and they made us pay, while we had the majority of the play.
“There were three really big chances for us in the second period, with Marquis and Evans both going close.
“Then there was a defensive header from Leadbitter that the keeper’s done well to keep out and prevent an own-goal.
“Sunderland defended their lead well, although we put too many balls into his hands, not giving our attackers enough of a chance.”
Ross McCrorie came on as a full-back during the second half and Jackett was pleased with what he saw from the on-loan Scotsman.
He said: “Ross did very well and gave us some thrust down the right that we were maybe lacking earlier in the game.
“After getting sent off on his debut at Shrewsbury, he was back on the pitch and I was impressed with his performance.”