Richard Kingson expressed his sorrow at the error, which cost Birmingham City the chance of opening Eric Black's reign with something other than a seventh defeat in eight games.
The Ghana international allowed Sully Muntari's 34th-minute drive to slip through his hands and inside his near post to gift Harry Redknapp's team a lead they rarely looked like losing.
To make matters worse Kingson was making his first Premiership appearance, following his summer transfer from Ankaraspor, and that error not only cost Blues vital league points but ensured he will remember his debut for all the wrong reasons.
Although he had already produced a diving save to deny Niko Kranjcar and went on to bravely tip Benjani's 62nd-minute effort away for a corner, Kingson was also beaten by the Croat's angled free kick with eight minutes remaining, though he felt he had no chance to stop it. But he could do nothing other than accept culpability for the opener which turned the match in Portsmouth's favour.
"I am very disappointed for me and the team," Kingson said. "I feel so bad about the goal, I was very sad. It is something I will have to overcome and move forward.
"It was not a lack of concentration but I didn't expect the shot because they [Muamba and Muntari] were coming together and the ball passed through Fabrice's legs. It was a difficult ball for me.
"I still have my confidence, many things happen in football but this will not take my morale from me."
Circumstances being what they are at St Andrew's, Kingson could be forgiven for feeling down. The managerial situation is shrouded in mystery - all that is clear is Blues have lost their most successful manager of the modern era, and Carson Yeung's takeover is faltering.
Indeed the 29-year-old admitted all the off-field uncertainty had an impact on the performance on it: "I arrived from Ghana only yesterday and trained yesterday," he said. "Training was slow, slow, slow. Usually you see more fire in training the day before a game. I think it [Bruce's departure] has affected everybody. I hope in the next game the fire will be there."
He also hopes he will be there too. Certainly caretaker manager Eric Black felt his goal-keeper needed to be supported rather than censured. "I believe he merited his chance," Black said. "It is a nightmare scenario for him and he will be as disappointed with the goal as anybody. "At half time I was trying to pick him up. He needs to be brave now, I am sure he will be fine."