Chelsea put one foot in the Champions League semi-finals after a disciplined 2-0 win away to FC Porto in the first leg of the quarter-finals on Wednesday night.
Mason Mount and Ben Chilwell got the goals for Thomas Tuchel's side at the Ramon Sanchez-Pizjuan Stadium, ahead of next week's return leg, which will be played on the same grounds.
Tuchel made a number of changes to his starting lineup, with Thiago Silva, who received a red card in the Premier League on Saturday, among those benched.
After a good start in the opening 10 minutes, Chelsea faded away as the Portuguese side grew into the game, harassing their opponents and pinning them down.
The first clear chance fell to the home side in the 12th minute as Mateus Uribe got a good chance to get on the scoresheet, but fired his shot inches over the crossbar from the edge of the penalty box.
The hosts then got a number of half-chances, but could not convert them as the Blues stood firm.
Tuchel's side then took the lead against the run of play, and it came courtesy of a moment of magic from the in-form Mount.
Jorginho showed great vision to find the youngster with a cheeky pass inside the box, and a half turn took the ball away from his opponent before a first-time shot sailed into the bottom left corner.
The hosts then had two chances to grab the equalizer before the break, but could not penetrate a well-organized defence.
First, Jesus Corona got to the rebound just outside the box, but his attempt was blocked by one of the defending players before Pepe tested Mendy in goal with a powerful header from a corner.
The second half was a balanced affair as the hosts pushed for the equalizer, keeping Mendy busy all night.
Moussa Marega in particular was a constant menace for the Blues' backline and felt he should have given a penalty after going down from a Cezar Azipilcueta challenge.
Despite their pressure, Chelsea created better chances, coming close on a number of occasions.
Christian Pulisic was unlucky after coming off the bench, crashing his shot against the crossbar in the dying minutes of the game.
The biggest moment of the second period came in the 85th minute as a mistake from the defence gifted a chance to a lurking Benjamin Chilwell, who kept his cool and rolled the ball into the net from close range.
Chelsea will feel confident going into next week's second leg, which will be played at the same venue due to travel restrictions as a result of the coronavirus.