Town boss Nathan Jones felt his side were "outstanding" in their defeat to Portsmouth at Fratton Park this afternoon.
A Jamal Lowe goal after 16 minutes was all that separated the two teams, as the Hatters saw a number of chances go begging.
The Welshman said: "I thought we were outstanding. They scored from a real error, we kind of won the first header but then it fell, Sheehan slipped, then we get done one-versus-one and they scored a decent goal. I thought we dominated the game – to come to Fratton Park and play like that, I am so proud of my team.
"We should have been comfortable, the chances we created, the type of chances. I don't know how thick the bars and posts are! But I thought we were brilliant. I am so proud of my team, to come into League One, to come here to the favourites or second favourites and to do that to them, I am proud. I am excited for what we can achieve.
"We carved them open time and time again. We weren't quite clinical, we hit the post, second half we were totally dominant. I am very proud.
"Portsmouth are a good side, they're fancied. To do that to them, I couldn't ask for a little bit more, but it's a learning curve, we might have got away with it on another day, we didn't today and that's the learning curve.
"If we want to mount a challenge then we have got to be right at it. There was two little defensive errors there, we should have done better on it and we didn't. Apart from that, our structure, how we competed, how we moved the ball, I thought we were excellent."