The Blues put the Armenian side to the sword at Stamford Bridge, racking up eight goals without reply on a record-breaking evening in the competition.

Despite the eyecatching scoreline, Maresca was at pains to underline what it was about his team’s performance that gave him the greatest satisfaction.

‘The players once again showed how professional and serious they are,’ he said.

‘It’s easy to sleep or fall down in this type of game. Football is full of surprises. What I asked them before the game was to show how serious we are, how professional, and they showed that.

‘If you remember, in the first five minutes we conceded a chance. If we had conceded, the game changes. You always have to be focused. You cannot drop. The way to show respect to them is not to underestimate them.

‘It’s an important message for all of us. If you are not ready mentally, you can drop easily against any team. The most important thing is that we are serious. This is what we needed to show.’

It was a good night for younger members of the squad and the club's academy.

Maresca handed a full debut to Tyrique George, a Chelsea debut to Samuel Rak-Sakyi, and saw 18-year-old Marc Guiu, signed in the summer from Barcelona, score his first goal for the club.

He said: ‘Tyrique was very good. I said before the game probably with young players sometimes it’s better to tell them the day before so they can prepare, but with some it’s better to tell them at the end so they don’t get nervous.

‘We knew already Tyrique was going to start, so I just told him two hours before the game. He was very good.

‘Also Sam Rak-Sakyi when he was inside was good, and I’m very happy for Marc Guiu that he scored. He hasn’t got many minutes with us this season, but he’s working hard.

‘They are 17, 18 and 19 so it’s important.’