Roberto De Zerbi said Tottenham's historic 2-0 victory against London rivals Chelsea proved his side have a winning mentality as they banished their dismal start to the season.
Tottenham won at Stamford Bridge in the Premier League for just the second time in 36 years and the first since 2018.
Trips across the capital to west London have largely been fruitless experiences for Tottenham over the last four decades.
But De Zerbi's men enjoyed a memorable visit to the Bridge on Saturday thanks to a comical own goal from Chelsea goalkeeper Mike Penders and a late wonder-goal from Mathys Tel after Blues star Cole Palmer was sent off.
"It was a big moment for the fans, the club and the players also. They deserved this win, they prepared very well," De Zerbi said.
"We are improving a lot, we are improving in the mentality, in the group and the relationships with the players and then we are improving on the pitch."
Tottenham started the season on a dismal run of six league games without a win, raising the specter of another relegation battle after they narrowly avoided dropping into the Championship on the final day of last season.
With the pressure mounting on De Zerbi, the Italian has drawn his players closer together thanks to meals together and a trip to Marbella.
- 'The spirit, the belief' -
A win against promoted Coventry on Monday lifted the tension around the north London club and vanquishing Chelsea was another reward for De Zerbi's team-building ethos.
"Now it is a complete team. When we stay for dinner and stay together in the dressing room, I see a different group, a different relationship and different atmosphere among the players," he said.
"The character was today great, but we have many, many new players. The players who stayed here last season, two or three seasons ago, they suffered the last results, two times 17th position, we are working to change the last part of the history of the club."
Tottenham were beginning to lose the faith of their long-suffering fans after another miserable start to the season.
But De Zerbi was adamant he never doubted they would get back on track.
"I have to believe for sure in this group. I never lost the confidence in my players," he said.
"The week in Marbella, to speak better face to face, to open ourselves and remove the mask it is important.
"It is important for the spirit, the belief. The atmosphere inside the dressing room is maybe more important than the tactics."
For Chelsea boss Xabi Alonso, it was a painful setback as the optimism engendered by successive victories over Bournemouth and Everton was washed away on a rain-lashed evening.
Alonso's expensively assembled team sit in fourth place but remain very much a work in progress after the third league loss of his first season in charge.
"We are all disappointed with the result, with the performance collectively and individually we were not at our best level," he said.
"It was about the first goal and it went their way and with 10 men it was difficult but we can do better."
Alonso refused to blame Penders and Palmer for their roles in the defeat.
"We feel for everyone, it is a team thing, a collective. We have to move on," he said before adding he "hadn't seen" Palmer's two bookings.
