The action-packed weekend tested traditional heavyweights while showcasing the thrilling, unpredictable nature of the league.

Here are five key takeaways from the most recent round of matches.

1. Arsenal's championship grit outlasts Chelsea's pretence

The marquee matchup at the Emirates Stadium proved to be an early-season reality check for Chelsea. Under Xabi Alonso, the Blues arrived with a perfect record and plenty of title hype, which only intensified when Morgan Rogers volleyed them into an early lead.

However, the reigning champions proved why they are the team to beat. Showing immense composure, the Gunners roared back through Kai Havertz and a winning goal from captain Martin Odegaard.

It was a stern lesson for Alonso's side on the difference between being a high-scoring outfit and a genuine title contender.

2. Alexander Isak is finally reborn for Liverpool

A torrid, injury-plagued debut season on Merseyside left many questioning Liverpool's English-record 125 million pound investment in Alexander Isak. Matchweek 3 suggested those doubts can be firmly put to rest.

The Swedish international struck a quickfire early brace at Portman Road, securing a clinical 2–0 away victory over Ipswich Town. It handed new manager Andoni Iraola his first official win in charge.

Having already equalled his entire Premier League goals total from last season, a fully fit Isak makes Liverpool an intimidating prospect once again.

3. Michael Carrick's defensive gamble is already costing Man Utd

Manchester United's attacking fluidness was on full display at the Hill Dickinson Stadium, with Bryan Mbeumo and Benjamin Šeško scoring excellent goals.

Yet, the recurring headline for Michael Carrick's side is a fragile rearguard.

United twice blew the lead against an Everton side managed by David Moyes, which had spent the closing hours of the transfer window in a state of attacking panic. Conceding twice - including a spectacular stoppage-time equaliser to debutant Ainsley Maitland-Niles - highlighted United's instability.

Choosing not to reinforce the backline before the deadline looks like a major oversight with the Manchester derby looming next weekend.

4. Hull City's unlikely resilience is turning heads

While the traditional heavyweights dominate the headlines, Hull City are quietly putting together the most surprising start of the season.

The Tigers ground out a highly respectable 0–0 draw against a dangerous Aston Villa side on Saturday, keeping their unbeaten start firmly intact. Most impressively, Hull have managed to navigate their opening three fixtures of the Premier League season without conceding a single goal.

Sitting pretty with seven points out of nine, they have shown a defensive structural maturity that many established top-flight teams currently lack.

5. Manchester City win ugly to stay perfect

Great teams find ways to win when they aren't at their sparkling best, and Manchester City under new manager Enzo Maresca proved that again.

Facing a stubborn, deeply disciplined Coventry City at the Etihad Stadium, the Citizens struggled to find their usual fluid rhythm. Nevertheless, City ground out a 1–0 victory to secure a perfect nine points from nine.

Alongside Arsenal, they remain the only perfect team left in the country, setting up what promises to be another relentless, standard-setting title race.

Real Madrid boss Carlo Ancelotti rules out any more signings