Chelsea manager Carlo Ancelotti felt striker Nicolas Anelka was the key to his side's 4-1 win over MSK Zilina in their Champions League group game.Anelka set up Michael Essien for the opener before scoring twice himself."The key was Anelka, he had a fantastic game. He created space, had chances and was the key," said Ancelotti."He can play the position in front, sometimes we use him more wide, sometimes in the middle but he shows the same skills if he plays wide."Daniel Sturridge scored Chelsea's fourth goal, while goalkeeper Petr Cech's error helped Zilina grab a consolation goal through Tomas Oravec."I think that Petr could do better with the goal we conceded but we faced a lot of crosses," added the Blues boss."I am happy Sturridge scored, but he has to improve his positioning, I would like him to play more infield rather than out wide."He showed fantastic movement to score, I am happy with his performance."Chelsea came under pressure late on when the game was won, but Ancelotti was unconcerned after his side took their goal tally to 21 from five games."Every game in the Champions League is hard to play," said the Italian. "We started very well in the first half, we played fantastic football but the second half was different."Zilina put more pressure on our defence. The back four did a good match. When you are 3-0 up it's normal to have more difficulty."I hope to watch my team play a fantastic game for 90 minutes. Obviously, I was a player so I know sometimes there are difficult times, the opponent can come back in the game."If I have to judge the performance I am very happy because it's not easy to win 4-1 away in the Champions League."Zilina coach Pavel Hapel believes the match would have been closer had his side shown a more ruthless edge in front of goal."I am not disappointed with the game," said Hapel. "We played well and attacked Chelsea. We managed to score so it was OK."We kept up with Chelsea as much as we could but I am disappointed with the productivity. The score was a surprise."We didn't show the same productivity in front of goal as Chelsea did."Source: BBC