But Italy midfielder Jorginho has called on the Blues to guard against complacency in Tuesday's second leg.

"We are all happy with this first result but for the second game we need to stay humble, we don't need to think that we have the advantage because it would be a big mistake," said Jorginho.

"We need to stay calm and focused because it is not easy if we do that mistake, we can be in trouble so we need to stay calm, be humble, work hard again, knowing that Porto is a very good team and we need to respect them."

Chelsea boss Thomas Tuchel branded the Blues' clean sheet against Porto as the perfect response to Saturday's hefty loss to West Brom, where Thiago Silva was sent off.

Jorginho delivered the ideal personal riposte after a below-par showing against the Baggies, angling a threatening ball to lay on the opening goal for the impressive Mount.

"There were things to look at and learn from that mistake (Saturday's defeat) and for us we know it is important to defend well as a team and not concede a goal," Jorginho told Chelsea's official club website.

"Everyone worked very hard and we left everything on the pitch so the win was deserved by the whole team, including those who helped from the bench.

"Mason was in a good position, he turned the right way. I just saw some space and I gave him the right ball for him to control and score."

Chelsea will face Crystal Palace at Selhurst Park in Premier League action on Saturday, before returning to the neutral venue of Seville for the second Champions League leg against Porto on Tuesday.

Stamford Bridge boss Tuchel was delighted to see his players hit back to form after that shock West Brom loss, with replacements Christian Pulisic and Olivier Giroud adding much-needed second-half impetus.

Timo Werner and Kai Havertz struggled for timing and rhythm, with Tuchel conceding the Germany duo had struggled against Porto.

"I wanted to give the sign that I accepted it was a bit of a tough match for Timo and Kai," said Tuchel.

"They had not their best days and the connection between the deep seven players that we needed for the build-up and the front three was a bit lost.

"The balls we delivered were not the best and I felt they did not play on their highest level so I wanted to have an impact from the bench because Christian is in a good momentum and Oli waited for so long and has good memories of the stadium.

"We wanted to give the sign that we keep on going. This is the mentality in general that I like about the club and about the team, and that we want to implement."