Gareth Evans is confident that Pompey can see off Sunderland when the sides meet at Fratton Park next week.
A fine strike from Chris Maguire saw the Wearside outfit secure a narrow advantage in the first leg of the play-offs.
They had Alim Ozturk sent off midway through the second half, but managed to keep the Blues at bay.
Evans believes it will be a different story on home soil, however, and has tipped his side to overturn their deficit.
The midfielder said: “Our dressing room wasn’t downbeat at all – we feel very positive that we can get the required result on Thursday at a packed Fratton Park.
“Sunderland had that one moment of quality for the goal and perhaps we didn’t make the most of them going down to 10 men.
"We’re more than capable of scoring two goals against Sunderland – and that’s what we feel we’re going to do."
“But we looked strong and resolute at the back and didn’t allow them to counter on us. It’s certainly not the worst result in the world.
“Now we need a positive performance and we’re going to have that 12th man on our side, which gives us an advantage.
“We’re more than capable of scoring two goals against Sunderland – and that’s what we feel we’re going to do.
“It’s effectively only half-time and we’re one down, which is what happened at Wembley in the Checkatrade Trophy, so we need to do it again.”
Ozturk was dismissed following a foul on Evans, who picked himself up to curl the resulting free-kick against the crossbar.
Pompey’s skipper said: “Clarkey played me through and I managed to get away from the defender. He’s taken me out and it’s a blatant red card.
“I thought the free-kick was heading for the top corner. Sometimes they go in and sometimes they don’t – unfortunately this time it didn’t.”