Chelsea won through five different goalscorers, with Marc Guiu, Moises Caicedo, Enzo Fernández, Estêvão and Tyrique George. Ajax also had skipper Kenneth Taylor sent off before halftime.
The win was achieved with Chelsea becoming the first team in the Champions League to have three different teenage goalscorers.
Maresca said afterwards: "Very proud. It's a special night for the club, for the young players.
"I think Guiu already scored for Chelsea five or six goals last year in the Conference. Ty already scored also in the Premier League. Estevao, exactly the same. I think overall it was a great night, especially for these young players and for the club.
"It's the strategy of the club. We have so many young players. I think already last season we were the youngest squad in the history of the Premier League, so this season we continue in the same way.
"We changed tonight from the Forest game, 10 players. It's not easy from the Premier League to the Champions League to change so many players, but we need to do that, otherwise they are going to struggle because of many games. We need to protect some of the players. Tonight I think was also good because we could rotate players, especially with the red card."
On their chances of winning the competition, Maresca also said: "We always say the same, but at the end it's because it's true. We go always game by game. I think tonight was good to win, to continue the momentum, but now in 48 hours we have one more game that is very demanding, Premier League game against Sunderland.
"I think it's good for everyone, for the club, but it's a win and personally it doesn't mean too much in terms of the season. It's just to continue to play games, to try to win, to try to improve players and this is the main thing."