"After not playing a couple of games, to come back into the team it was important for me to get confidence back by scoring," said Kalou.
"All the boys were saying after I missed the first opportunity, 'Don't worry about it, it will come', and I'm happy it came in the end."
Kalou added that it was more important to pick up the points and avenge Saturday's Premier League loss to Aston Villa and was certain it would fill all the players with some much-needed confidence after a bad week.
"It was very important to win that game because it gave us nine points," he added.
"It's good to get confidence back by winning and everyone gave his best today and we have the result in the end.
"After the disappointment of last week [against Villa] we had the opportunity to show it was a mistake."