Tottenham Hotspur suffered their worst home defeat in Europe as Serge Gnabry scored four times in Bayern Munich's 7-2 romp to seize control of Champions League Group B on Tuesday.
Master marksman Robert Lewandowski also scored twice as Bayern responded to going behind in devastating fashion.
When Son Heung-min gave last season's runners-up Tottenham a deserved 12th-minute lead, the home fans were buoyant but their hopes were crushed as Spurs leaked in seven goals at home for the first time in any major competition.
To make matters worse for Mauricio Pochettino's shell-shocked side it was a Gnabry, a former Arsenal player, who was the architect of their humiliation.
"I never dreamed I'd score four goals," Gnabry said. "The pressure helped. My father told me I had to play well."
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In a rip-roaring start to the first clash between the sides for 35 years, Son had twice wasted guilt-edge opportunities before firing Tottenham in front.
Tottenham were still posing a threat in a wide-open game but three Bayern goals in 10 minutes left their hopes of a first win in Group B in tatters.
Lewandowski has already bagged 10 goals in six Bundesliga games this season and showed why he is one of the world's most-feared strikers as he beat Lloris with a shot on the turn seconds before the halftime interval.
If that was a cruel blow for Tottenham, what happened in the opening minutes of the second half was crushing.
Gnabry, who suffered several frustrating years at Arsenal, shredded Tottenham's defence in the 53rd minute to score a breathtaking solo goal and struck again two minutes later.
But Bayern were in ruthless mood.
Gnabry completed his hat-trick in the 83rd minute, racing on to Thiago Alcantara's long ball and the wrong-footing Lloris with a classy finish.
With the home fans flooding towards the exits and Bayern's followers joyfully singing "football's coming home", the visitors piled on the agony.
Lewandowski was played in by Philippe Coutinho and finished in deadly fashion and with Tottenham's defence AWOL again, Gnabry put Niko Kovac's team in seventh heaven.
Bayern top Group B with six points from two games with Tottenham on one. Red Star Belgrade are second with three points after beating Olympiakos 3-1.