The Hatters got a 1-1 draw at the Stadium of Light and are currently second, four points behind Pompey.
Sunderland are third but with a game in hand.
It was a good point for Luton after a tough weekÂ with manager Nathan Jones having joined Stoke.
Interim manager Harford praised the players and believes with the ability they showed they will be right in the mix for one of the two automatic places toÂ go up.
Speaking to Luton's official website lutontown.co.uk he said: '˜We're a group, we're a good group. They all want to contribute, they manage themselves basically.
'˜The team that went out there, they managed themselves.
'˜You've got your senior players who know the routines of what we do and what we're about.
'˜So it's been a whirlwind, but we move on, the football club goes on and we're really looking forward to the challenge.
'˜But if we put in performances like that, then we will definitely be pushing for promotion out of League One.'
Harford felt the game was of a higher quality than the level it was played at.
He added: '˜It was very, very eventful and I am proud of the players, the players were magnificent.
'˜They've gone out there, played a style of football, and Sunderland, that was above the level in terms of where we are.'