The German international admits that the physical nature of Sunday's clash took him by surprise, while describing his first strike for the Blues as a "special" moment of his career.
He told the club's official website: "It's so special for me to finally score my first goal for Chelsea, and also at home in a big game. I will never forget this.
"It was a perfect afternoon for me and for the team because Fernando scored at the end and we won. That was the most important thing.
"It was one of the hardest matches I've ever played in. It was very physical out there. The tempo and the intensity were unbelievably high, everyone was giving 100%."
The 22-year-old's maiden Chelsea goal came in his 11th appearance for the club, as he looks to become an established regular on the left flank under manager Jose Mourinho.