Whew!

What a first weekend it was in the Premier League. We had upsets, amazing goals, and a high-scoring thriller between two of England's elite clubs.

All in all, it was a wild weekend, but this is becoming the norm for the Premier League.

Yes, there is one more fixture left in the season's first week as Chelsea and West Ham United kickoff Monday afternoon, but let's take a look at three takeaways from the opening weekend.

Pep Guardiola Doesn't Guarantee Anything

Undoubtedly one of the greatest managers in the world, Pep Guardiola's track record speaks for itself. He's won a total of six league titles across seven seasons with Bayern Munich and Barcelona, although his sides at each stop were overflowing with world-class talent.

Since he's won big everywhere he's been, it may have been easy to expect him to do the same at Manchester City, especially with no dominant teams currently reigning supreme in the Premier League. Well, Saturday's nail-biting home win over Sunderland proved it's not going to be that easy.

Obviously, it was just one game -- and a season-opening fixture where City wasn't at full strength -- but Guardiola's troops failed to overpower lowly Sunderland, needing a late break to snatch a very unconvincing 2-1 win.

The own goal saved City, a team with title aspirations, from the embarrassment of a home draw against a Black Cats side that finished 17th a year ago, just two points clear of relegation.

City's other goal came from a penalty, so they failed to score an open-play goal against Sunderland, who conceded a whopping 62 goals in 38 Premier League matches a year ago.

Guardiola is a gaffer of the highest quality who will undoubtedly win a lot of matches with the Citizens, but capturing a Premier League title will be a challenge, especially with the quality of the managers of England's other top clubs.

Liverpool May Not Be Great, But They're a Lot of Fun

In his first full season since taking over midway through last year, manager Jurgen Klopp has his work cut out for him to get Liverpool into the top four. But Klopp has started tweaking the roster and bringing in the players he wants to run his system.

Much like Pep Guardiola's famed tactics, Klopp's system -- which emphasizes relentless pressing to win the ball back and then going forward quickly -- needs certain types of players, most notably ones with pace, stamina and tactical ability. Klopp and the Reds haven't made a plethora of transfer moves, and as a result, the roster is in a sort of middle ground. While several current players certainly fit the mold of Klopp's type of footballer, others don't.

This isn't great for Liverpool's chances of achieving big things this campaign, but a flawed team -- particularly one that's quite a bit better right now going forward than it is defensively -- makes for some entertaining play.

Philippe Coutinho is the embodiment of this.

Coutinho scored one of the season's best goals on the opening weekend a year ago, and the Brazilian started off this campaign with another golazo. He rifled home an inch-perfect free kick just ahead of the halftime whistle to pull Liverpool even with Arsenal after 45 minutes.

It's another doozie in a lengthy line of long-range beauties from Coutinho, whose flair and guile leads to him trying things most players wouldn't dare attempt. The peach free-kick was just one of Coutinho's many contributions before he limped off injured midway through the second stanza.

Coutinho added another goal on a deft deflection and ran away with WhoScored.com's Man of the Match honors as the Reds sprinted out to a 4-1 cushion before holding on for a 4-3 victory.

Liverpool could certainly put together a top-four campaign this season -- Klopp has excelled against the top teams -- but they're going to be a dream side to watch even if they miss out on the Champions League.

The Reds have been the highest-scoring Premier League team since the calendar flipped to 2016 -- netting a league-high 43 goals -- and as they showed against the Gunners, their offensive abilities have only been strengthened by the signing of Sadio Mane, who himself scored a magical solo goal in the season-opening win.

We're in For Another Wild Year

The Premier League, at the current moment, doesn't boast any club who could argue for a spot among Europe's elite, but what England does feature is a lot of pretty good teams and some incredible parity.

When the big boys and perennial title contenders -- Chelsea, Manchester City, Tottenham, Liverpool, Manchester United and Arsenal -- get together, it's going to be awesome.

None of those sides can hold a candle to Real Madrid, Bayern Munich or Barcelona -- the world's top teams -- but they're all talented, boast high-level coaches and not much separates them. The wildly entertaining affair between Liverpool and Arsenal was a good example of this.

The race for the top four is going to be bonkers.

While the parity at the top of the table is nice, no league features as many crazy, unpredictable fixtures as the Premier League. It's how Leicester City can win the title at 5,000-to-1 odds last season -- although something that insane may never happen again -- while super-spenders Chelsea finished in 10th.

This was on display during Matchweek 1.

Everton, a mid-table club and Tottenham, statistically the top team in the league a year ago, played to a 1-1 draw that was more even than the score indicates. Defending champions Leicester were knocked off by newly-promoted Hull City, who was just the fourth-best team last season in England's second tier, and Manchester City narrowly edged Sunderland, a relegation candidate, thanks to an own goal.

It's going to be another crazy year in the Premier League. Buckle up.