In a frantic opening 45 minutes, the Eagles twice fell behind before eventually taking the lead and their place in the fifth round.
Two goals from Marouane Chamakh on his return from injury and a debut strike from loanee Yaya Sanogo; cancelled out Graziano Pelle???s opener and Scott Dann???s own goal.
Pardew said: “I thought he (Chamakh) was the best player on the pitch today. When you think about (the) players Southampton have got, that’s a real credit to him.
“He has been injured. The guys said to me ‘you’re going to get a lift in the team when you see him play???. I’ve not really seen a lot of Chamakh in my time.
“He did particularly well at the back end of last year, but I don’t think even then he put in a performance as good as a today. He really was very good.”
Pardew also had praise for striker Sanogo – “I think Arsene Wenger will be very pleased”, he said – after what was a thrilling cup tie against his former club.
“We worked on our attacking play this week and it was great to see that we had that flamboyance in our play today,” the Eagles manager said following a fourth straight win.
“We have good defenders so I was really pleased with the way we went about trying to attack Southampton because they are difficult to attack.
“They keep possession and they kind of get you drawn down. They got the first goal and I thought ‘hmmm, this could be difficult’, but we got the immediate equaliser, which helped us, I think, and increased our belief.
“Then it really was a great first half. Both teams I thought were terrific and we came out just on the right side of it.
“The second half was different. We locked it up a little bit and had to defend very, very well. In terms of a cup tie, I thought it was terrific. Both teams, really, deserved a lot of credit.”