Ralph Hasenhüttl was left disappointed by his side’s defensive display as Southampton suffered a 3-1 defeat on the road at West Ham.
The hosts took the lead early on as Jarrod Bowen punished Saints for giving the ball away, before Michael Obafemi restored parity with half-an-hour played.
However, the Hammers were to take a lead into the break as Sébastien Haller beat Alex McCarthy to the ball in the air, with all three points confirmed after the restart courtesy of Michail Antonio.
“We conceded three goals and they conceded only one and the reason is because they defended better than we did,” Hasenhüttl said.
“The first goal was in the box and only running with the man and not really stopping him shooting on goal, which is absolutely not the way we can defend.
“The second goal I don’t think I have to explain, everyone saw what happened with Alex [McCarthy]. The way we defended, I think the guys know it was far away from what we wanted to do.
“We knew the long balls and the strong guys up front but it’s not enough to know it, you’ve got to defend it well and we didn’t.”
Victory for the Hammers saw them record the league double over Southampton after picking up a 1-0 win at St Mary’s back in December, leaving Hasenhüttl in a reflective mood.
“We had nearly the same situation in the last game against them, but today we were still not good enough.
“We must find a way to defend against such teams or we will have more time where we lose like this.”