LONDON – Tottenham Hotspur suffered their heaviest home defeat in Europe as Serge Gnabry struck four goals for Bayern Munich in a 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 early on in devastating fashion, running riot on a rain-lashed night in north London.When Son Heung-min gave last season’s finalists Tottenham a deserved 12th-minute lead, their magnificent stadium was rocking. But the fragility that has undermined their season so far returned as they capitulated in alarming fashion.It was the first time Tottenham have shipped seven goals at home in any major competition and they became the first English club to concede seven in Europe since they themselves lost 8-0 to FC Cologne in the now-defunct Uefa Intertoto Cup in 1995.To add insult to injury for Mauricio Pochettino’s shell-shocked side it was a Gnabry, a former Arsenal misfit who managed one goal in a handful of appearances, who was their chief tormentor with a sensational display.While Tottenham’s season continues to misfire, Niko Kovac’s Bayern appear to be going from strength to strength.It was not quite the Bavarians’ biggest away win in Europe — they won 7-1 at Roma in 2014 — but to do it against a side who reached last year’s final sent out a powerful message.“It didn’t look like (a) 7-2 (match) after 30 minutes. We had our problems at the back and (Manuel) Neuer kept us in the game with some class saves,” Kovac told reporters.“After that, we were much better. We scored at the right time. Getting the second before the break was key.”Pochettino has enjoyed unforgettable European nights as Tottenham manager but this will go down as one of his lowest moments since he took charge in 2014.“Bayern were clinical and scored with every single touch,” he said. “That is tough to accept but we need to move on. We need to be strong and keep going, stay together…not to find guilt or try to escape. It is the only way to recover.”Bayern lead the group with six points with Red Star Belgrade on three after beating Olympiakos who are level with Tottenham on one point after their 2-2 draw on matchday one.Chances flowed like the rain in a rip-roaring start to the first clash between the sides for 35 years.Gnabry stung the finger of Hugo Lloris inside two minutes before Son was twice denied by Neuer after being played in one-on-one by Tanguy Ndombele.When Bayern gifted possession to Tottenham in the 12th minute, Ndombele found Son again and this time the South Korean beat Neuer with a powerful angled drive.Tottenham’s inability to hold a lead has been a feature this season and within three minutes Bayern were level thanks to a precision effort from distance by Joshua Kimmich.Harry Kane had an effort cleared off the line soon after but they were pole-axed by three Bayern goals in a 10-minute spell.Lewandowski has already bagged 10 goals in six Bundesliga games this season and his hot streak continued seconds before the interval as he turned and fired home from the edge of the area after Tottenham had failed to clear the ball.It was harsh on Tottenham but things only got worse.Gnabry shredded Tottenham’s defence in the 53rd minute with a jet-heeled burst down the left before cutting in to arrow a shot past Lloris and he struck again two minutes later.Kane’s penalty restored some hope for Tottenham on the hour after Danny Rose was adjudged to have been fouled and substitute Christian Eriksen forced a fingertip save by Neuer.But when Gnabry completed his hat-trick in the 83rd minute, racing on to Thiago Alcantara’s long ball before sliding a cool finish past Lloris, the home fans flooded towards exits.With Bayern’s fans joyfully singing “football’s coming home” Lewandowski scored a brilliant second from Philippe Coutinho’s pass — taking his Champions League haul to 56 in 106 games.Tottenham’s defence went AWOL again as Gnabry put Bayern in seventh heaven with his fourth.