Manager Neil had yet to taste defeat on the road since taking over at Norwich in January but admitted his team did not deserve anything from Sunday’s encounter.
The visitors struggled to impose themselves on the game following Steven Whittaker’s first-half dismissal, with Graziano Pelle handing Southampton the lead just before the break.
Sadio Mane and Dusan Tadic inspired Saints to victory in the second period, with the latter adding a brace to leave Neil disappointed.
“I thought we looked too comfortable and didn’t move the ball well enough and didn’t work hard enough,” he said.
“The type of team we are, the way we play, we have got to be up for the battle and I don’t think we won our individual battles as well as we normally do.
“I think it is more disappointing in the manner in which we lost the record rather than the record has gone. If my team had played well today and given everything they had got the record wouldn’t have bothered me as much.”