Thomas Tuchel says Mason Mount's first Champions League goal was a "big step" for the player as Chelsea established a commanding quarter-final lead.
Mount set the Blues on their way to victory over Porto, with Ben Chilwell adding a second to give Chelsea a 2-0 first-leg lead.
England midfielder Mount, 22, has scored three goals in his past four games for club and country.
"The finish was clinical and excellent from Mason," said Chelsea boss Tuchel.
Mount's clever turn and finish in the first half helped bring some welcome relief to Tuchel after his side's heavy defeat to West Brom on Saturday, which was followed by a training ground incident between team-mates Kepa Arrizabalaga and Antonio Rudiger.