"There were three or four players who inspired us against Southampton and if we are honest all eleven had to be inspirational at times," Keegan told the official club site.
"This is a tough place to come, they ask a lot of questions from you and you have to come up with the answers and on Saturday we did. We thoroughly deserved to win at St. Mary's and over the last two years not many teams have been able to say that."
And only now can Keegan claim any victory over the Saints - the weekend's 2-0 triumph is the first time one of his sides have beaten them.
In particular though, Keegan was pleased with the improving form of his £7 million striker.
"The only thing that has been missing for Robbie is the goal. His work rate, his enthusiasm, his willingness to chase has been there for four weeks and longer than that on the training ground.
"It has taken a bit of time and a little bit of luck to get the goal. Anyone who has been watching us will know every time we have got a deflection it has been Robbie with a shot which has just gone wide.
"But there was no doubting that his goal against Southampton was world class, he is a world class player. We believe in him, he believes in himself again after a really traumatic two years out with injury."
And Keegan is confident this will continue. He added: "We will now reap the rewards of that over the coming months and years."