While a single goal separated the sides, Chelsea controlled the game and avoided being unsettled by defender Thiago Silva limping off with a thigh strain in the first half.
"It's the style the manager wants us to play and it's been working well," said Mason Mount, so often the impetus of Chelsea's attacking threat. "It's new, it's different for some of us players. We're all learning but it's obviously going well so far."
While Chelsea's pursuit of the Champions League places was given a lift, Tottenham are slipping away from the top four in a disappointing second season in charge for Mourinho.
Tottenham are seven points from fourth in eighth place having played a game less, and are sorely missing the injured Harry Kane, who could return from ankle injuries next week. Tottenham were also beaten at their stadium by Liverpool last Friday, before collapsing at Brighton 1-0 on Monday.
Mourinho, though, wasn't so pessimistic.
"In the second half, we were different, the spirit was different, the confidence, too," Mourinho said. "At the end, the feeling that I have is that the team stuck together until the end, fought until the end ... and to finish the game with this positive spirit helps."
Still, the situation at Spurs seems miles away from the glory days of Mourinho's two spells at Chelsea, when he lifted the Premier League trophy three times and turned Stamford Bridge into a fortress. Given the team's slump, Mourinho will be hoping Tottenham chairman Daniel Levy is more patient than Chelsea owner Roman Abramovich.
It was Abramovich's restlessness that saw Mourinho fired twice, part of a managerial carousel at Chelsea that also led to Lampard being dismissed last week.
Chelsea had been leaking goals under Lampard but have yet to concede in three games under Tuchel.
"Every experience we make is a step forward if we are open to learn from it," Tuchel said.
Tottenham's poor performance also raised questions why winger Gareth Bale was left on the bench. However, Mourinho wouldn't say why Bale — back on loan at Spurs from Real Madrid — is overlooked so often.
Mourinho was much more vocal criticising the penalty decision against Dier that few neutrals would dispute.
"It is a penalty that is difficult to accept. So to lose the game to a penalty like this is a bit painful."
- AP