Timo Werner’s first-half header put the Premier League side in front on aggregate and then followed a nervy hour or so until Mason Mount’s late strike sealed the victory.
Real Madrid, toothless and sluggish throughout, were unable to respond, and Chelsea will now face Pep Guardiola’s Manchester City in Istanbul later this month.
Here are five things we learned.
Persistence pays off for Werner
It has been an odd first season at Chelsea for Werner. His potential is clear, but it is hard to describe his finishing as anything other than wasteful.
The possibility of another frustrating night in front of goal seemed high when the German converted early in the first half only for the flat to go up for offside. Soon after, though, he was on hand to follow up a delicate Havertz lob, which struck the crossbar and dropped a yard out. Werner duly headed home.
That will have come as a relief for the 25-year-old, however easy the finish. A crucial goal on such a big occasion can only boost his fragile confidence.
Hazard’s struggles continue
The narrative was set up perfectly: Eden Hazard, after his problems with injuries and consistency since his move to Spain, could remind the world of his talent on his return to Stamford Bridge. But that didn’t happen.
The Belgian was largely anonymous, marshalled expertly by Andreas Christensen and unable to impact the game. He was not alone, of course, given the subdued nature of Real Madrid’s performance.
Still, this will have been a disappointment for Los Blancos’ supporters. Big things are expected of Hazard given his previous achievements, but with each appearance in a white shirt hope dwindles.
Mendy proves his worth
Chelsea defended superbly as a unit but there were inevitable moments of individual quality from the visitors.
Karim Benzema produced the best of them and twice brought sensational saves from Edouard Mendy. His first effort, a curling save from the edge of the box, forced the goalkeeper to stretch to his left and tip the ball wide.
Then came a powerful header from close range, which Mendy pushed over the bar with an acrobatic leap. Given the close scoreline, these were important moments.
Chelsea were not indebted to the goalkeeper, because for the most part Real Madrid’s attackers were kept quiet. But Mendy is establishing himself as a reliable No.1.
Ramos return not enough for Real
The return of Sergio Ramos should have been reassuring for Real Madrid. Instead, though, they looked dishevelled and almost rudderless.
There was certainly an element of rustiness about the veteran defender, who has so often been the driving force behind Real’s success in this competition. Chelsea created a host of chances and repeatedly got in behind Ramos, Nacho and Eder Militao.
His presence was not enough for the Spaniards on this occasion, although he did, of course, pick up his customary yellow card. Some things never change.
Havertz growing more influential
Like Werner, Havertz has endured periods of difficulty after his summer move to Stamford Bridge.
But he is really starting to find his feet now. The 21-year-old is in a settled role, operating just behind Werner, and looks like the player Chelsea fans expected to see when he arrived for £75.8m from Bayer Leverkusen.
Havertz was unfortunate not to score on the night, hitting the woodwork twice - the first of which rebounded perfectly for Werner to nod home - and missing a one on one with Thibaut Courtois in the second half.
Aside from a little profligacy, though, there were more hugely promising signs here for the Germany international.