The Blues came into the match on the back of a shock defeat to west London rivals QPR and fell behind to a Jay Rodriguez effort after 22 minutes. Chelsea, though, rallied to turn the game on its head, running out 5-1 victors as Victor Moses, Branislav Ivanovic and Lampard efforts complemented a Ba brace.
"The first half we had to work but after that little by little the team was getting better," he said. "The second half was much better. We played with quality and when you're one goal ahead they have to take more risks."
He added: "It is always important for a striker to score goals but more than just the goals it is the contribution for the team. The understanding of things we were talking about like how to know the movements of other players, he was very clever and could understand everything."
Ba's display was so impressive that Fernando Torres, a player rejuvenated under Benitez, was left on the bench at St Mary's.
"I prefer this problem than just to have just one," the Chelsea boss said when asked if the pair will prove a selection headache. "It is important for the team to have these different options, good players."
Southampton had lost just two of their last 10 games and Nigel Adkins knows his side were well beaten.
"What he have to do is put the game to bed, move on and look to the next one," he said. "We've got a week's recovery and preparation now after a busy fixture period. Hopefully it gives one or two of the lads that have been out a chance to recover and we get ready for Aston Villa."
A bad afternoon was made worse for Saints when centre-back Jose Fonte was stretchered off in the second half. The Portuguese left St Mary's on crutches and in a leg brace with what Adkins confirmed was a knee injury.
"It is not good when somebody gets stretchered off," he said. "He is being assessed now so I don't know the extent of the damage. It is a knee injury he has picked up but I don't know what yet."
- Sports & Recreation