Lee Bowyer believes Charlton will not be beaten over two legs in a play-off semi-final.
Bowyer’s men are four points clear of seventh-placed Plymouth, who have two games in hand.
Bowyer, who said Charlton needed to win three of their remaining four games after losing to Scunthorpe last weekend, told News Shopper: “That was just a wild guess. I still think we need to win our two games.
“Win both and then whoever is in the play-offs, teams think ‘wow, they've just won seven out of 10’.
“Once we’re in the play-offs, I honestly believe there is no team that will beat us over two legs.
“I’ve said that since the moment I took over. It’s not that I’m disrespecting anybody, I just believe in my squad of players. So I honestly believe that.
“Everybody wrote us off because of the games that we weren't doing so well in, five points out of it, we were written off. But now they've turned it around and that’s from fighting.”
Nicky Ajose’s 40th-minute goal was enough to down Portsmouth in a game where Charlton could have scored more.
Bowyer, who has won five of his eight games in caretaker charge, hailed the togetherness of his team.
He added: “I’m really proud of the players. To go to Shrewsbury on Tuesday night and put the effort and commitment in that they did and to have this quick turnaround and come to Portsmouth, a ground that’s probably the most intimidating place in this division, and put in that effort and fight, the togetherness was outstanding.
“It’s something I demand. I’ve been in a lot of dressing rooms and you can’t compete with that. If you have a togetherness and a team spirit, then that gives you an edge over the other side.
“Once you've got a togetherness and fight, you'll run that extra mile for your friend. If you see your friend’s out of position, you'll do it. If you don't have that togetherness then you won’t do it.
“Everyone is running around like mad to help their friends out. They're covering each other, they're fighting, someone goes in for a tackle and a team-mate is behind them.
“That’s what you need to be a winning, successful team and that’s what I’ve demanded from the minute I took over.
“You can tell by the performances. Maybe against Scunthorpe we didn't compete, but that was down to tiredness, that’s the only game where we weren't ourselves.”
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