Luton boss John Still felt his side were lacking in the final third as they lost 1-0 to AFC Wimbledon at Kenilworth Road.
Barring one Luke Guttridge effort, Luton, who had scored over 100 goals on their way to the Conference title, failed to test Dons goalkeeper James Shea enough and Matt Tubbs' 41st minute goal proved to be the winner.
Still said: "I was really happy with how we played and if I'm disappointed, it was our final third play, final pass, final cross, final finish.
"It wasn't quite on it, but in general, I was quite happy with how we played. It's the last bit of the jigsaw.
"We've worked really hard pre-season, looked sharp and scored goals in pre-season. We carved out eight, nine, 10 good opportunities to deliver the ball in and it wasn't quite right.
"In the first half we had 75, 80 per cent of the game and the longer the game went, I thought we pushed and we pushed.
"We found a way last year and we'll find a way this year. It's really important we don't over focus on what was not quite right, but we focus on all the good things we've been doing and fine tune a little bit."
The Hatters bossed possession and territory early on, but only had Guttridge's fierce drive from close range, excellently parried by Shea to show for their efforts.
They paid the price too as in the 41st minute Adebayo Akinfenwa's flick-on was latched upon by Tubbs who finished clinically beyond Mark Tyler.
The visitors should have been 2-0 ahead moments after the restart as Akinfenwa headed wide at full stretch, while Sean Rigg was denied by a brave Steve McNulty block.
Town upped the tempo as Guttridge's back post header flew just wide, while Mark Cullen sent a low 20 yarder against the outside of the post.
Dons boss Neal Ardley thrilled to come away with a first win of the campaign against a team considered title favourites.
He said: "For 20 minutes it was what we expected. The first game back in the league for a while for them, a great atmosphere, Stilly's teams, really well drilled, coming at us, putting us under pressure.
"The moment we started getting it down and playing we got a little bit more of the game.
"The goal's helped us in the first half and what a great goal, Tubbs' finish was different class. Second half I thought we had enough chances to score four in the end.
"All in all, it's a very good day for us. There won't be many teams who come here and beat this lot."