Liverpool and City are both primed to reach the last four after quarter-final first leg wins but Thomas Tuchel's Chelsea have bowed out.
The Blues were brilliant against Real Madrid but lost their quarter-final tie 5-4 on aggregate.
Real will now meet City in the semi-finals if Pep Guardiola's men progress.
Villarreal pulled off a stunning win over Bayern Munich in the other quarter-final tie.
And Liverpool look the most likely to face them in the final four after beating Benfica 3-1 in Lisbon.
Liverpool overcame Inter Milan with a 2-1 aggregate victory in the last-16, while City and Chelsea made light work of Sporting Lisbon and Lille respectively.
The Champions League semi-final dates are expected to take place on Tuesday, April 26 and Wednesday, April 37 for the first-legs.
The return fixtures will then be on Tuesday, May 3 and Wednesday, May 4.
The final will take place at the Stade de France in Paris on May 28 after it was moved from St Petersburg following Russia's invasion of Ukraine.