Hatters had won eight out of 10 of their friendlies, but turned in a desperately poor first half showing at Haig Avenue and were eventually beaten 1-0.
Guttridge said: “There were absolutely no excuses, we just weren’t good enough.
“It’s hard to say, but personally, it was down to attitude. I think we thought because we had a good pre-season, we’ll turn up and win the game.
“Complacency is a massive thing in football. One good game doesn’t make a season, you can go through all the cliches in the world and they seem to come out in football.”
Guttridge wasn’t overly panicking though as he experienced something similar at Northampton Town last season and felt this wake-up call could work in their favour.
To view the footage of the Sandgrounders goal from Southport FC’s Keith Brady, click the link above.
For the full story, see the Luton News/Dunstable Gazette on sale tomorrow, while for all the latest Luton Town FC news, reports, stats, player profiles, live match updates, MOM poll, prediction table and a complete fixture list, visit our Hatters Microsite.