Norwich City pulled off one of the shocks of the season, as they defeated the current defending champions and favourites for this season's trophy Manchester City 3-2 at Carrow Road.
The Canaries were playing in England's second-tier as recently as last season, and despite having won the Championship last season, the sheer difference in size and quality of players between them and Manchester City saw the visitors installed as overwhelming favourites to claim all three points.
Furthermore, Manchester City have not lost in the league since a 3-2 reversal to Crystal Palace back in January, while Norwich were also injury-plagued and missing no less than eight first-team players.
However, in scenes which sent shockwaves across the world of football, Norwich raced into an early 2-0 lead, but when Sergio Aguero halved the deficit right on the stroke of half-time, it seemed like the template had been set for a second-half onslaught by Guardiola's men.
This proved to however not be the case, as another goal by Norwich five minutes into the second half put Manchester City further behind and even though they ultimately scored a late second through Rodri to set up a grandstand finish, the hosts ultimately held on for what would go down as one of the biggest upsets in the league this season.
As indicated, Manchester City were heavily tipped to win this match, and we shall be highlighting three reasons why The Cityzens fell to the surprise defeat.
#3 Teemu Pukki's inspired form
Norwich won the Championship last season, and Teemu Pukki had a large role to play in their triumph, scoring 29 goals from 43 matches to help his side win promotion back to the Premier League.
The Finnish international has had a journeyman career, turning out for no less than eight clubs in six different countries, but despite not really being prolific at either of his former clubs, Pukki has settled right at home with Norwich.
For all of his Championship heroics, there were many who expressed cynicism over Pukki's ability to perform in the Premier League, as numerous players in the past have found the step up in class and level a bit too tough to handle.
However, Pukki has put all cynics to shame, as he has totally outperformed everyone's expectations, scoring five goals and registering one assist from his first four matches in the Premier League and also scored while on international duty with Finland.
For his efforts, the former Celtic man was named as the first PFA Player of the Month this season, and he continued from where he left off in the game against Manchester City.
Pukki was on hand to set up Todd Cantwell for Norwich's second, while he got his sixth goal of the season five minutes into the second half.
H currently finds himself leading the race for the Premier League Golden Boot, and if he continues in this for, there could be no stopping him as Manchester City found out to their peril.
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#2 Uncharacteristic errors by Manchester City players
While Manchester City might be almost pristine in their attacking fluidity, their defence is an entirely different proposition and leaves a lot to be desired.
Though they rarely concede goals and keep lots of clean sheets, this is down to the ability of their midfielders and continuous attacking play rather than the individual brilliance of their defenders, as Manchester City's possession-based style of play means the ball is constantly in the opposition half, giving them limited chances of testing their goalkeeper.
Aymeric Laporte's knee injury robbed Guardiola off his most reliable defender, and in his stead, the much-maligned John Stones stepped in to partner Nicolas Otamendi at the heart of the defence.
This was a pairing that was fully exploited by the Norwich attack, as they forced the City backline into numerous errors and duly punished them for it.
Kenny Mclean was left totally unmarked from Emi Buendia's corner for Norwich's opener, while Teemu Pukki caught the Manchester City defenders out of position before teeing up Todd Cantwell for the home team's second.
The Cityzens' hopes of a comeback were dealt a major blow when John Stones and Nicolas Otamendi showed a great misunderstanding which led to the Argentine being dispossessed by Brenda en route Pukki scoring Norwich's third.
Further up the other end Manchester City were also uncharacteristically sloppy, and failed to take their chances, while also failing to play the right final ball with Bernardo Silva being the chief culprit.
Manchester City under Guardiola have earned a reputation of being pristine in their play down to the last detail, but against Norwich, the reverse was the case and they paid dearly for it.
#1 Daniel Farke played Manchester City at their own game
Norwich City won plenty of plaudits with their expansive style of play in the Championship last season, scoring goals for fun and imposing their will on opponents, with the 93 goals they scored last season by far the highest of any of the 24 clubs in the league.
However, a major drawback of their style of play was that it left them exposed at the back, evidenced by the fact that they conceded 57 goals from just 46 matches.
Once their promotion was ascertained, a major topic of debate was whether Norwich would stick to their attacking style or shelve it for a more restrictive and cautious approach to avoid getting whitewashed by much better opposition in the Premier League.
An example of a side who stuck to their attacking principles but got blown away upon promotion was Fulham just last season, but despite the Cottagers' recent misfortune, Norwich City's manager Daniel Farke was unequivocal in his stance that his side would maintain the same style.
They won plaudits for playing against Liverpool but ended up losing 4-1, and it was a similar story in their 3-2 loss to Chelsea.
For all of their impressive play, Norwich headed into the game against Manchester City with just three points from a possible 12 and coming up against the league's deadliest and most potent side, the home side would have been forgiven for retreating and protecting their goal.
However, that did not happen, with Farke's side giving as good as they got, putting Manchester City on the backfoot with their constant pressing and forcing them into making errors.
Goals cannot be scored without taking attacking risks and while it might have been a perilous game to play against the defending champions, Norwich City ultimately got their rewards.