Klopp’s Liverpool went into the game on an eight-match unbeaten run and looked for all the world like extending that after a first-half in which they were by far the better side.
But, with the Reds losing for the first time in Premier League history after leading 2-0 at half-time, Klopp was at a loss as to the contrast in displays either side of the interval.
“I saw lot of good things from my side,” he said. “It was a perfect first half and we could have scored more. We played really good.
“In the second-half Southampton deserved it. We could have done better but that’s how it is in football. You have to take your chances and in the first moment of the second half I saw it was not too good.
“It was clear when they scored their first goal that something big would happen in this game. We could have played better. It is like it is. Second half Southampton deserved the three points.”
Despite the set-back, Klopp has refused to give up on taking Liverpool into the top four before the end of the season.
“There are nine games left, still 27 points to get,” he added. “If we can get all of them there is a chance.”