Chelsea head coach Thomas Tuchel heaped praise on midfielder N'Golo Kante after witnessing his side record a 2-0 victory over Lille on Tuesday night.
Goals from Kai Havertz and Christian Pulisic ensured that the European champions will travel to France for the second leg in control of the last-16 tie.
Despite not getting on the scoresheet in the Champions League fixture, Kante received the Man Of The Match award, and Tuchel acknowledged that the Frenchman had produced 'a game-changing performance'.
Speaking to BT Sport, Tuchel said: "I was very pleased today, it took him a while. He struggled in the last matches with his belief and intensity and game in general.
"It was good he stepped up today and you can instantly see the impact he makes. He is our game changer. He had a huge impact on the team."
Chelsea received a double injury blow during the second half as Mateo Kovacic and Hakim Ziyech both sustained injuries which make them doubts for Sunday's EFL Cup final with Liverpool.
