Alan Pardew felt that the start to the second half was where the match against Plymouth was lost.
The manager felt that his side had put in a good first half display which may have worked against them as the visitors came out all guns blazing at the start of the second 45 minutes which earned the Pilgrims an unlikely 1-0 win.
"I think that's the first opening day match I've lost," Pardew told Saints Player. "The team looked well placed at half time to go on and win the game, we hadn't got a goal but we looked terrific.
"Unfortunately the first ten, fifteen minutes of that second half cost us the result today. They came out obviously steamed up after a disappointing first half from their side, and we have to be able to match that, but we didn't. That cost us a goal, and unfortunately cost us the game.
"We had some good quality in and around the box, the ball was flashing across and they had a few breaks. When you come here, if you want to win then you will have to have a few breaks go your way, and I thought they did. They were diligent, they blocked, they got things in the way, even at the end there we had two or three great chances and their bodies were finding their way in front of our ball into the back of the net. It was a lesson for us."
The lack of a Saints goal naturally drew questions about the impact of Rickie Lambert's absence from the side and the gaffer is hopeful he will soon be able to call on last season's top goal scorer in English football.
"Well I would like to have said we could have been leading the game two nil and our strikers had got two, but they didn't. You are going to miss the likes of someone like Rickie Lambert, he's not too far away, he was touch and go to include him on the bench, but we couldn't take the risk. We might see him at MK Dons.
"It's just one of those typical first games of the season, we were so dominant that we probably felt that we were going to go on and win the game. For ten minutes we just lost our way, we forgot that we have to put all the hard work in and everything else that goes with getting promoted. In doing so we conceded a goal and then got frustrated, we went off the game plan a little bit, but that's the things we have to learn as we go. There's a bit to do, but we will focus on the next game and hopefully get a win.
"Someone else is probably favourites (for the title) now, that's the beauty of football! There is a lot of focus on us and we will have to deal with that.
"It's not the day we wanted and we aren't going to mask over it, it is a disappointing day and we are maybe going to have another six or seven to live with, but no more than that. We should set our standards high, and the most immediate thing is the reaction in training on Sunday and Monday, and then a positive performance on Tuesday.
"There will be pressure on us now, and we have created that on ourselves, so it's important that we get a positive result."
