Chelsea boss Jose Mourinho said there was nothing emotional about Frank Lampard's goal against the Blues, and insisted the "love story" finished when the midfielder joined Manchester City.
The 36-year-old former England international, who left Chelsea in the summer, came off the bench to equalise in the 1-1 draw at Etihad Stadium.
"Frank Lampard is a Man City player," Mourinho told Sky Sports.
"When he decided to go to a direct competitor then love stories are over."
The Portuguese coach added: "I don't believe in stories of passion and heart, maybe I am too pragmatic in football. He did his job as a professional."
|Lampard gives Mourinho the blues|
|Frank Lampard scored 211 goals in 648 appearances for Chelsea between 2001 and 2014|
|His strike for Manchester City against Chelsea means he has now scored against a record 39 different Premier League clubs|
|It was the former West Ham midfielder's first goal against the Blues in his 11th match against them|
Lampard's goal came on his home debut for City, having joined the club on loan from Major League Soccer side New York City.
It cancelled out Andre Schurrle's opener for Chelsea, which had come minutes after the hosts had Pablo Zabaleta sent off for a second bookable offence after fouling Diego Costa.
The equaliser denied Chelsea the chance to move five points clear at the top of the Premier League.
"I feel that when a player leaves another club and plays for a direct opponent, he is not going there for a holiday, he is going there to try and beat his club - the one everyone considers the club of his heart, but not any more," Mourinho told BBC Sport.
"Maybe again [Chelsea will be in his heart] when he leaves City, but while at City he wants to beat Chelsea. That is the nature of football."
Lampard was applauded by both Manchester City and Chelsea fans when he came on with 12 minutes remaining.
"The reception I got when I came on was amazing, I can't speak highly enough of the fans," he said.
"I came here to do a job and it was a special and weird day. It was a difficult day for me at the end because what do you do? You're caught in the middle.
"What was a win for me today? Maybe a draw and keeping the Premier League close and a reception from both sets of fans that I won't forget."