Thomas Tuchel praised Mason Mount after the youngster’s first Champions League goal helped Chelsea win the first leg of their quarter-final against Porto 2-0 in Seville.
Mount opened the scoring in fine style, collecting Jorginho’s pass and spinning away from a challenge before firing into the far corner of the net.
And Ben Chilwell netted a potentially decisive second away goal for the Blues.
Boss Tuchel said: “The finishing was excellent from Mason. He has the quality to do this and to do it in a quarter-final is a big step for him.
“He’s a very important player for our squad at a young age. I can only repeat: he has the right mentality and right attitude towards training and games.
“He has the right attitude towards success. He has both feet on the ground. He’s open and hungry to learn.
“He’s a key player for us and I’m happy that he fits in this role at such a young age. It’s good to have him.”
Tuchel was also pleased with the impact made by Olivier Giroud and Christian Pulisic after they came on as a second-half substitutes.
They replaced Timo Werner and Kai Havertz, who had struggled up front.
Pulisic fired against the bar after being set up by Giroud shortly before Chilwell’s goal.
“I accepted that it was a bit of a tough match for Kai and Timo today,” Tuchel explained.
“They had not their best day and we did not deliver so good. We lost a bit of the connection to them.
“The balls being delivered were not the best balls and they did not play on the highest level today.
“So I wanted to have an impact from the bench. I was happy about the impact from the substitutes.”
Chelsea are overwhelming favourites to reach the semi-finals but Tuchel warned that the job is only “half done” and that another strong performance will be needed in the second leg, which will also be in Seville.
“We’re happy but not too happy. Excited but not over-excited,” Tuchel declared.