Billed as a showdown between Mourinho and Lampard, an explosive London derby showed the student is more than a match for the man who served as his mentor during their time together at Chelsea.
Blues boss Lampard pulled a tactical masterstroke as he cleverly changed his team's formation, leaving Tottenham manager Mourinho unable to respond as Willian opened the scoring with a blistering strike and increased Chelsea's lead with a penalty before half-time.
Tottenham's South Korean star Son was sent off for a needless kick at Antonio Rudiger in the second half as Chelsea swept to a sweet victory over their former manager.
With top four rivals Manchester United losing at Watford earlier in the day, it will be a happy festive period for Lampard's fourth placed side, who sit six points clear of seventh placed Tottenham after ending a run of four defeats from their last five Premier League games.
There was little Christmas cheer for Tottenham, who may have to answer for the behaviour of their fans amid claims Rudiger was racially abused and an object was thrown at Chelsea keeper Kepa Arrizabalaga.
A fan was seen directing a 'monkey gesture' at Rudiger and three announcements over the tannoy that "racist behaviour from spectators is interfering with the game" painted a bleak picture of the latest racist incident to scar European football this term.
Lampard had already beaten Mourinho last season when his Derby met the Portuguese coach's Manchester United in the League Cup and once again he proved too smart for his old boss.
After a hug and handshake between Lampard and Mourinho, there was a poignant minute's applause for Tottenham and England World Cup winner Martin Peters, who died aged 76 on Saturday.
Those shows of respect marked the end of the civilities as Tottenham fans booed Marcos Alonso vociferously and chanted about his involvement in a fatal car crash in Spain several years ago.
Tactical tweak
Chelsea had the perfect response to the cruel taunts as they completely dominated possession in the early stages and took the lead in the 12th minute.
With Tottenham too slow to mark up, Willian took a short corner to Mateo Kovacic and when the Brazilian received the return pass, he adroitly side-stepped Serge Aurier before curling a superb finish into the far corner of Paulo Gazzaniga's net.
There was an extra edge about Willian's celebrations given the abuse of Alonso as he sprinted to pose in front of the Tottenham fans.
Aware of Chelsea's frailties at the back, Lampard had switched to a five-man defence and dropped Jorginho in a move that allowed N'Golo Kante to return to his preferred deep-lying midfield role.
The tactical tweak worked a treat and Tottenham's only decent chance of the entire match was wasted by Harry Kane, who fired over from Moussa Sissoko's cross.
With the supply lines to Kane shut down, Lampard's team deservedly doubled their lead in first half stoppage-time.
To the chagrin of Tottenham's fans, Alonso was the catalyst as he chased a long ball into the penalty area and was clattered by Gazzaniga's desperate rush off his line.
After a VAR review, the spot-kick was awarded, with Willian calmly slotting past Gazzaniga for his fifth goal of an exceptional campaign for the winger.
That made it an alarming 14 goals conceded in all competitions by Tottenham since Mourinho replaced Mauricio Pochettino.
Any hopes of a Tottenham comeback were quashed in the 62nd minute by Son's needless clash with Rudiger.
Falling to the turf after a collision with the Chelsea defender, Son responded by kicking both feet at Rudiger.
A lengthy VAR review led to Son's dismissal for violent conduct, sparking an ugly end to the clash as Tottenham fans appeared to tarnish their club with sick racist taunts at Rudiger.
‘Firm action’
In regards to the racist chants, Chelsea boss Lampard wants firm action from the authorities, but he insists there was never any question of his team walking off the pitch in protest.
"All I know is Toni Rudiger said he heard racist chanting. I haven't had a conversation with him. Of course I support him," Lampard said.
"I don't know if it is getting worse. Of course we know there is a protocol. It needs to be dealt with strongly no matter what stadium it is."
Tottenham manager Mourinho made it clear he can't abide racism, but he then took a swipe at Rudiger, effectively accusing him of play-acting to get Son sent off.
"I hate racism in society, I hate racism in football. I'm disappointed that things like that can happen. The club is a very proud club in this kind of situation and internally we will try to deal with it," he said.
Pressed on Rudiger's theatrical fall, Mourinho added: "For me it is not a red card. For me it was really bad and basically kills the game.
"Rudiger for sure is having scans in the hospital on the broken ribs because it was really a violent situation!
"One of the reasons I felt in love with this country was we don't call this kind of player a clever player, we call them other things that I refuse to say."
Lampard disagreed, saying: "It was a red card. Sometimes in football you have instinctive moments and it was that moment for Son. I would not have any words said about how Rudiger dealt with that."
'Thorough investigation'
Meanwhile, a subsequent Tottenham statement said the club were "conducting a through investigation" that would include liasing with Chelsea players and staff.
"Any form of racism is completely unacceptable and will not be tolerated in our stadium," the statement added.
"We take any such allegations extremely seriously and shall take the strongest possible action against any individual found to be behaving in such a way, including stadium bans."