Real Madrid coach Zinedine Zidane opted for a switch in formation due to the number of injuries he had to deal with as Ferland Mendy, Sergio Ramos, and Fede Valverde were unavailable for the game. Tuchel continued to deploy Cesar Azpilicueta at right wing-back with Mason Mount, Timo Werner, and Christian Pulisic as the front three.
It was a thoroughly entertaining 90 minutes of football at the Alfredo Di Stefano stadium which got off to a flying start after Christian Pulisic blitzed past the Blancos' defence to score a brilliant goal in the opening 15 minutes. The American ran circles around Real Madrid's backline and beat Thibaut Courtois to slam the ball into the net.
Real Madrid then hit back via the brilliant Karim Benzema as the Frenchman turned up for the occasion with a brilliant volley from a short-corner routine. The goal sparked Zinedine Zidane's side back to life after a suspect first quarter of the game. Both sides adopted a bit more of a cautious approach once the weather got worse as it led to a number of slips, mistimed tackles, and misplaced passes from both sides.
In the end, although Chelsea have the added advantage of an away goal to their name, the tie remains well-poised and is set up for a blockbuster return leg in West London.
Here are some of the major talking points from the game.
#5 Chelsea could rue their first-half wastefulness
Chelsea began the game with a brilliant spell and were easily the more dominant side in the first 30 minutes. The likes of Pulisic and Mason Mount were too quick to handle for the hosts and they opened up the visitors on a handful of occasions. Naturally, this led to a fair few chances which they could have and should have put away.
Timo Werner was wasteful against Real Madrid, and failed to score what should have been an early opener for the Blues. Mount picked out a perfectly weighted cross to find Pulisic who then set up Werner with a lovely header. The German failed to convert from a few yards out. A minute later, Azpilicueta delivered another fantastic cross into the box and Werner failed to get to it by some distance.
As the game went on, Real Madrid regained some sense of control but the first half hour of the game was an uncharacteristically sluggish and sloppy display from the hosts, which Chelsea should have capitalised on even further. With some of Real Madrid's injured stars likely to return to fitness before next week, they could live to regret missing those chances.
#4 Marcelo's inverted role didn't help Real Madrid
Marcelo is no longer capable of covering the length of the pitch as he did a few years ago and this is one of the reasons for him losing his place to Ferland Mendy, who has covered the most distance in this season's UCL (102,703m). Mendy's absence was felt by the side as Marcelo stepped in for him on Tuesday, and didn't do a particularly great job.
When in possession, the Brazilian veteran tucked into midfield on a number of occasions, allowing Vinicius to drift into wide areas to try and get in behind Azpilicueta, like he did against Trent Alexander-Arnold. It was a failed experiment in both ways as Vinicius didn't get the better of the diligent Azpilicueta who was watchful of the Brazilian, while Marcelo was a passenger in the middle.
He failed to keep up with Chelsea's lightning-quick transitions and he was run over time and again. There was a moment in the second half when he fouled an onrushing Pulisic in Chelsea's half of the pitch as he knew he couldn't keep up with the winger's pace, which perfectly summed up his outing on the night.
#3 Chelsea expose Real Madrid's lack of cohesiveness
Zidane's starting XI could have been very different had Ramos been available, and to cope with the absence of his injured stars, the coach picked a back five of players who have never played together. Dani Carvajal, Nacho, Raphael Varane, Eder Militao, and Marcelo have never started a game next to each other for Real Madrid, and their lack of cohesiveness was exposed by the visitors.
Chelsea's pacy forwards ran riot over their defence in the first half and their runs in behind caused them all sorts of problems and pressed them relentlessly. Their lack of coordination was evident, at least until much later on into the game, and they had to resort to committing fouls more often than not. It was only the second time in Zidane's managerial career in the UCL that he's deployed a back three, and he's done so only on four occasions this season in LaLiga Santander.
In stark contrast, Chelsea's XI were extremely cohesive and played like a brilliant unit in which every single player was perfectly aware of the role that needed to be performed. They shut out the explosive Manchester City in the FA Cup semi-final with the same set-up and kept 16 clean sheets in 21 games, and while they might not have a shut out to show for, Tuchel still won the tactical battle against Zidane.
#2 N'Golo Kante wins battle vs jaded Real Madrid midfield
N'Golo Kante has been in sublime form over the course of the 2020/21 campaign, putting in a string of brilliant displays for the Blues. Under Tuchel, the French star has formed a formidable partnership with Jorginho, and on Tuesday, the pair won the midfield battle against arguably the best midfield in the world.
For all their accolades, Toni Kroos, Casemiro, and Luka Modric looked jaded against Chelsea, due to the immense workload and lack of able deputies available at Real Madrid's disposal. Kante was superior to every other midfielder on the pitch and gave Chelsea the upper hand as he won the ball back tirelessly. The Frenchman's lung-busting runs into Real Madrid territory were too much for the Blancos stars to handle.
Kante attempted more duels on the night than any player on the pitch (21) and his game-high six dribbles were more than all the Real Madrid players combined. He was often the spare man in midfield who caused Real Madrid's midfield all sorts of problems. Kante was a phenom and continues to deliver for Tuchel's side.
#1 Brilliant Benzema turns up once again
Karim Benzema has, more often than not, been the man to spare Real Madrid's blushes. He turned up to keep them in the competition with a season-defining brace against Borussia Monchengladbach and kept them in the title race with an 88th-minute equaliser in the Madrid derby. Against Chelsea, it was Benzema who once a gave them a fighting chance heading into the second leg.
In a half where his side were run ragged by an energetic Chelsea side, Benzema was excellent, and every touch he took was a measured and meaningful one. He warned Edouard Mendy, who was mostly a spectator, with a venomous shot that grazed the post in the first half. Six minutes later, he was on the end of a short-corner routine and controlled the ball with his head before lashing it home on the volley.
It was Benzema's 28th goal of the campaign and he's continued to turn up for his side time and time again. If Real Madrid have any hope of turning it around in the second leg, it's only because of Benzema's brilliance on an otherwise forgettable night for Zidane's side.