Two goals from Emmanuel Adebayor added to one apiece from Paulinho and Nacer Chadli condemned the hosts to a heavy defeat - their fourth straight reverse at home in the league.
It was a result that left manager Pardew questioning his side's work ethic and courage as they were outclassed.
"It was a tough night really," he said. "The performance wasn't good enough as we got dominated from start to finish, which sums it up.
"I think for the first time we really didn't look confident. We didn't look like we knew what we were doing.
"I thought we lacked energy in certain areas. Of course, I'm not happy.
"This is a game that, as a manager, you expect life and limb on the football pitch. I don't care what the scoreline is or what the scenario is, that's what I expect. If we don't do that then we will suffer.
"Paul Dummett and Mathieu Debuchy were the only two players who could come out with any credit.
"The players had better get the message as they're going to get it this week."
‘I don’t think Liverpool would look at Ollie Watkins, a striker isn’t a pressing issue for them – it’s Arsenal who need one’ Former Reds star explains why his old club don’t need an out-and-out forward this summer
‘He’ll still be playing at 40 at a good level because he’s in such good shape and looks after himself so well. He does everything to be a top professional’: Ex-Liverpool coach insists Mohamed Salah has plenty more miles in the tank
