Chelsea ended Saturday sitting second in the Premier League table.
The Blues have played one game more than Manchester City, Liverpool and Bournemouth, who all play on Sunday, but a win before the international break leaves a positive feeling around the club.
Chelsea are also the division’s top scorers with 21 goals from 11 games, but that would have been a difficult statistic to believe during a first half played at a lethargic pace.
“I was very worried before this game,” said Maresca. “These are the worst games, they’re tricky. Everyone is thinking it’s going to be easy.
“I can understand in the first half people were not happy because we didn’t score. Then when Estevao came on the energy raised because people love that kind of player.”
The 18-year-old Brazilian has largely been limited to substitute appearances in the Premier League as he acclimatises to English football.
Maresca said this week that the youngster, who moved from his homeland in the summer, had complained about the cold weather in London, and the manager warned him to expect it to get worse before it gets better on that front.
“You can see his talent,” said Maresca of Estevao. “We are trying to help him to adapt and give him the right minutes.
“He arrived from Brazil, he needs time to adapt, but he’s going to start games for us in the future.”
Chelsea next face a trip to Turf Moor after the international break to face Burnley on 22 November.
They remain in the EFL Cup, where they have had a seemingly favourable draw away to League One side Cardiff City in the quarter-final, and they have a glamour game at home to Barcelona in the Champions League coming up three days after the Burnley test.
Star attacker Cole Palmer is due back from injury in December, which could provide a further boost as Chelsea aim to qualify for the Champions League through at least a top-four or top-five finish this season.
Maresca’s “word hard” message to Garnacho is reflected in his wider view of how Chelsea can reach their targets.
He said: “Inside, we are convinced that as a club, as a team, we are going in the right direction and we are doing good things. At the same time we can do many things better.”