Glyn Hodges admitted he instructed AFC Wimbledon to run the clock down before Terell Thomas’ header sunk Pompey.
The defender's 93rd-minute header delivered the Wombles a 1-0 victory over Pompey at Kingsmeadow on Saturday.
Thomas’ effort piled more pressure on Blues boss Kenny Jackett, with sections of the away supporters in the terrace behind the dugouts chanting for his dismissal.
With Wimbledon also struggling in League One, Hodges would have been happy to take a draw,
But the Dons caretaker manager heaped praise on the late quality his side showed.
Hodges told londonnewsonline.co.uk: ‘The free-kick at the end – I was saying take it in the corner and wind the clock down.
‘But we’ve got the quality in the team. Max Sanders put the ball in and Terell Thomas finishes it.
‘We’ve always been in games and it’s always been close.
‘Look at the defeats – it’s always been by the odd goal. Maybe the chances just weren’t being taken. On Saturday, we had two one-on-ones and I thought it was going to be one of those days again.
‘But winning’s a habit and losing’s a habit – we want to get in the habit of winning again. We weren’t at our best and we still got the result, that’s the most pleasing thing.
‘We just seemed to hang in there. We had the attitude to stay in the game and you’ve always got a chance at 0-0.’
Wimbledon picked up a third successive win and moved up to 20th in the League One table on 12 points.