Millen's View: Pompey home 2-1
But It took a brilliant goal from Albert Adomah to finally find a chink in the Portsmouth defence, the first time they have been scored against in 636 minutes.
He cut inside, exchanged passes with David Clarkson and beat Jamie Ashdown from close range.
Nicky Maynard beat the offside trap before crossing and defender Greg Halford put the ball in his own net for the second on 65 minutes.
Pompey managed an injury-time consolation through Dave Kitson.
Millen said: 'I reckon one more win will see us safe now in the Championship and we are still aiming to finish in the top half of the table.
'It was our fourth successive win and a reward for determination and hard work against a very good side with many talented individual players.
'We were a bit open to begin with, but made one or two adjustments after which Portsmouth caused us relatively few problems.
'It was an absolutely brilliant goal by Albert Adomah and perhaps it was always going to take that sort of strike to get through a defence who had gone so long without conceding.''
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