The 21-year-old centre-back got the nod to start alongside Kurt Zouma and Andreas Christensen at Stamford Bridge on Tuesday and he was in magnificent form for the Blues in their opening Group H fixture.
Aside from his defensive contribution, Tomori earned Chelsea a penalty after Daniel Wass blocked his header with his hand but Ross Barkley failed to convert it three minutes from the end of regulation time.
Rodrigo Moreno’s 74th-minute goal separated both teams on Tuesday night but Tomori is pleased to have made his maiden appearance in the Champions League.
“There are top teams in the Champions League and it is always the fine margins, you know if you switch off for a split second those are the kind of moments that can turn the game. We are disappointed but we still have five games to go and we have to focus on Sunday as well," Tomori told the club website.
“Obviously, it is the biggest competition in the world and to be playing for Chelsea at the Bridge, to make my debut, it is something I wanted to do, I dreamt of and so I am very proud.”
Next up for Chelsea is a Premier League fixture against Liverpool at Stamford Bridge on Sunday and Tomori is hoping they bounce back from Tuesday's defeat and extend their unbeaten run in the English top-flight to five games.
“That's what football is all about and that is the good thing about being in a big club, having so many games and you can move on from the last one if you ever have a negative result. So definitely, we move on to Sunday,” he added.