Serge Gnabry stunned Chelsea with two goals in quick succession to inspire Bayern Munich to a 3-0 win at Stamford Bridge.
Gnabry scored a brace in the space of three minutes in the early stages of the second half to send Bayern towards a comfortable victory.
Robert Lewandowski added the third in the 76th minute and Marcos Alonso was sent off in the dying stages.
Chelsea will travel to Munich for the second leg in over three weeks, although Bayern look to have ended the tie as a contest after such an emphatic victory.
Tireless Chelsea Restrict Bayern to Scraps
Bayern Munich dominated possession but Chelsea worked tirelessly to reduce them to limited opportunities.
William Caballero foiled Robert Lewandowski twice and Kingsley Coman struck an early effort into the side netting. But Thomas Muller came closest for Bayern when his unorthodox header came crashing off the crossbar.
Muller also watched his speculative strike from range whistle just wide of the far post.
The Bundesliga leaders set-up with a four-man attack and Muller looked the likeliest man to unlock Chelsea’s robust defence.
He was incessantly floating between the lines and was at the heart of everything good going forward for Bayern.
Chelsea also had chances of their own but a poor final ball from both Mason Mount and Ross Barkley squandered numerous chances.
The Blues’ collective high-press flustered Bayern on occasions and Chelsea should’ve capitalized when Manuel Neuer gave the ball away cheaply just after the half-hour mark.
Marcos Alonso was a major driving force down the left and he came closest for Chelsea when his low driven strike was expertly palmed to safety by Neuer on the cusp of half-time.
Another magical European night for Gnabry leads Bayern to victory
Chelsea’s hard-work was completely undone within the space of three minutes just after the interval. Gnabry scored two goals in quick succession to hand Bayern a significant lead heading into the second leg in Munich.
The second half started promisingly for Chelsea, who forced a double-save out of Manuel Neuer. Jorginho scooped a menacing ball forward and Neuer impressively thwarted Mount and Barkley from close range, although the linesman later raised his flag on the nearside.
Jorginho talked his way into the referee’s notepad for dissent and will miss the second leg at the Allianz Arena. And moments later Chelsea collectively lost their composure and Gnabry and Lewandowski carved through their defence like butter to give the Bavarians the lead.
Boateng towered above Giroud at the half-way line and Thiago drove an incisive pass into the feet of Gnabry. Azpilicueta slipped at the decisive moment and Gnabry glided away from him before steering a reverse pass into Lewandowski.
The Polish international timed his delivery to perfection and Gnabry was presented with the simplest of finishes to score his fourth goal in as many games.
Bayern continued their momentum immediately from the restart and Gnabry ended the match as a contest with his second goal of the night just three minutes after scoring his first.
Neuer launched a speculative ball into the Chelsea half and Lewandowski knocked the ball down for Gnabry. The pair combined once again, carrying the ball forward with an effective change of passes. Lewandowski eventually rolled the ball behind the Chelsea defence and Gnabry confidently stroked his finish into the far bottom corner.
Gnabry could’ve completed his hat-trick when Muller generated yet another opportunity. He hooked an inviting cross into the penalty area but Gnabry uncharacteristically lacked composure and blasted his volley over the crossbar.
Bayern put the contest seemingly out of reach
Frank Lampard looked to change his side’s fortunes from the bench by replacing Giroud and Barkley with Abraham and Willian respectively. He also introduced Pedro later in the half, but nobody could prevent Alphonso Davies sprinting away from the Chelsea defence to break into the penalty area.
Lewandowski instinctively positioned himself in space and Davies simply squared the ball to him for another simple finish.
Their misery was compounded when Alonso was dismissed with seven minutes of normal time remaining. The Spaniard allowed his frustration to get the better of him and recklessly swung his arm in the face of Lewandowski.
Goretzka also came close in stoppage time but his header was blocked. The only downer for Bayern was another injury to Coman, who was replaced by Philippe Coutinho after 66 minutes.
Chelsea’s chances of progressing further in the Champions League are hanging by the thinnest of threads. The evening started promisingly for the hosts but their collapse after the interval set the tone for a humiliating evening against far superior opposition.
CHELSEA: CABELLERO (7), AZPILICUETA (PEDRO 73’), CHRISTENSEN, RUDIGER, JAMES, JORGINHO, KOVACIC, ALONSO, MOUNT, BARKLEY (WILLIAN 61’), GIROUD (ABRAHAM 61’). Subs: KEPA, ZOUMA, EMERSON, GILMOUR, PEDRO, WILLIAN, ABRAHAM.
BAYERN MUNICH: NEUER, PAVARD, BOATENG, ALABA, DAVIES, KIMMICH, THIAGO (GORETZKA 90’), COMAN (COUTINHO 66’), MULLER, GNABRY (TOLISSO 85’), LEWANDOWSKI. SUBS: ULREICH, ODRIOZOLA, HERNANDEZ, TOLISSO, COUTINHO, GORETZKA, ZIRKZEE.