Kenny Jackett explains his positive tactical switch for Portsmouth at Luton

The Blues endured a grim opening 45 minutes as a rampant Luton tore into them in last night’s top-of-the-table clash.

James Collins’ goal deservedly earned the hosts a 1-0 lead at the interval, when the scoreline could have been even more emphatic.

That prompted Jackett to introduce Omar Bogle and Dion Donohue at the break, coming on for Brett Pitman and Gareth Evans.

While Pompey’s boss also replaced his back-three system with a more conventional 4-3-3 formation.

And while the final outcome was a 3-2 loss, the Blues can be heartened by an excellent second-half showing.

Jackett said: ‘We had to try to get two up front at times, on too many occasions we just haven’t had any forward thrust.

‘In the first half we tried to get Lee Brown out and in space and, ultimately, he did that, but didn't have anyone to cross it to.

‘In the second half the centre-forward change helped us, it gave us some momentum and gave us some forward passes. He was occupying the centre-halves better than we could in the first.

‘We also brought Bryn from the left to the right, with it not quite being Gareth’s night, and gave us a natural balance in midfield with Dion’s left right.

‘Bryn transferring to the right of a midfield three was not a big difference, but he still got into the game quite well in the second period, when he didn’t in the first half on the left.

‘Donohue has a nice left foot and I do think can play it forward, while when he gets going can get some shots off as well, which is important.

‘After that first half we needed to come back, Luton were the better side and deserved their lead.

‘During that period I didn’t think we had enough forward play - and it has been like that for a couple of games.’

Jackett, however, was disappointed in the manner of George Moncur’s 85th-minute winner.

In particular, the decision to award a free-kick for Anton Walkes’ challenge on the substitute, who would net from the dead ball.

Jackett added: ‘We didn’t quite get the rub of the green in terms of some of the decisions, we accept that, that’s the way it is away from home.

‘It didn't look a free-kick, but in the end he (the referee) has given it and we have to defend it.

‘Moncur’s struck it well through a crowd of players, in terms of our wall and our chargers. He struck it very, very well into that far corner.’