Jurgen Klopp is arguably the best manager in world football right now as Liverpool have won the Champions League and then the Premier League title under the German tactician's tutelage.
After beginning their title defence strongly with wins over Leeds United, Chelsea and Arsenal, a visit to Villa Park to face Aston Villa was seen as a relatively straightforward challenge for Jurgen Klopp and his men despite the absence of winger Sadio Mane and first-choice goalkeeper Alisson Becker.
However, Aston Villa dealt Liverpool a stunning 7-2 defeat in perhaps the biggest upset in Premier League history as it marked one of Jurgen Klopp's heaviest defeats in his storied managerial career.
Arch-rivals Manchester United had lost 1-6 to Tottenham Hotspur earlier in the day, but Liverpool's result against Aston Villa overshadowed the events at Old Trafford.
On that note, let us take look at the five heaviest defeats suffered by Jurgen Klopp.
Jurgen Klopp's five heaviest defeats in his managerial career:
#5 SV Waldhof Mannheim 4-0 Mainz
Jurgen Klopp was appointed the manager of German second-division club Mainz in February 2001 where he went on to establish himself as a firm fan favourite.
However, in June that year, Mainz were beaten 4-0 by SV Waldhof Mannheim. A first-half goal from Lamine Cisse was subsequently followed by three in the second half as a brace from Hungary international Laszlo Klausz and a goal from German midfielder Hajrudin Catic sealed the deal for Mannheim.
Jurgen Klopp would go on to achieve promotion with Mainz in 2004, enjoying success in the top-flight of German football for three seasons before Mainz were relegated. Klopp then left the club in 2008.
#4 Borussia Dortmund 1-5 Bayern Munich
After leaving Mainz in 2008, Klopp became the manager of Bundesliga giants Borussia Dortmund a few months later, armed with the task of bringing back the glory days to the club.
In 2009, however, a Der Klassiker meeting between Borussia Dortmund and Bayern Munich resulted in a heavy loss for Jurgen Klopp's men. Centre-back Mats Hummels scored early for Dortmund before Bayern Munich established their dominance in the game in ruthless fashion.
A brace from young German forward Thomas Muller and goals from striker Mario Gomez, midfielder Bastian Schweinsteiger and France international Franck Ribery were enough to secure a comfortable win for the Bavarian giants.
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#3 Manchester City 5-0 Liverpool
Jurgen Klopp's Liverpool were starting to establish themselves as a genuine threat in the Premier League, but their progress was halted by a 5-0 loss against Manchester City in 2017.
Senegalese winger Sadio Mane was sent off in the first half for a high boot on Manchester City goalkeeper Ederson who was subsequently substituted. Pep Guardiola's side wrecked havoc even as Jurgen Klopp withdrew key forward Mohamed Salah for midfielder Alex Oxlade-Chamberlain.
Braces from young Brazilian forward Gabriel Jesus and Germany international Leroy Sane as well as a goal from veteran striker Sergio Aguero showed Manchester City's strength and depth as they romped to the Premier League title that season.
#2 Mainz 1-6 Werder Bremen
Mainz were in the Bundesliga in 2006 but were struggling to stay afloat. They sat 17th when they faced Werder Bremen in October and were handed a hiding as they conceded six goals at home in a lopsided defeat.
Werder Bremen, who had a good squad that season with the likes of centre-back Naldo, Germany international Miroslav Klose, young centre-back Per Mertesacker and midfielder Tim Borowski, would go on to finish third in the Bundesliga that season.
Bremen enjoyed complete dominance over Jurgen Klopp's Mainz, with Klose opening the scoring in the 14th minute. German midfielder Aaron Hunt then doubled the lead as Klose and Hunt both went on to score two goals apiece in the game.
Mimoum Azaouagh scored from a direct free-kick for Mainz, but Naldo and midfielder Diego ensured that Jurgen Klopp's men suffered a heavy defeat.
#1 Aston Villa 7-2 Liverpool
Premier League fans were in shock yesterday when Manchester United lost 1-6 to Tottenham Hotspur at home, but the Liverpool result managed to overshadow the events at Old Trafford.
Jurgen Klopp's Premier League champions were the overwhelming favourites for this game despite the absence of Sadio Mane and Alisson Becker. However, Liverpool were in for a shock at Villa Park.
New signing, forward Ollie Watkins who cost the club a record £28 million, scored a hattrick, captain Jack Grealish netted a brace and midfielders John McGinn and Ross Barkley scored a goal apiece as the Premier League champions suffered one of their worst hidings in history.
Mohamed Salah scored two goals for Liverpool, but to little avail. Goalkeeper Adrian was seen as a major disappointment, but Liverpool's defence were clearly not at their very best as Jurgen Klopp endured the worst defeat of his managerial career.