Chelsea ended title rivals Liverpool's perfect start to the Premier League season in a thrilling 1-1 draw at Stamford Bridge. Champions Manchester City are top on goal difference from Liverpool, while Manchester United's 3-1 loss away to West Ham raised fresh questions over the future of manager Jose Mourinho at Old Trafford.

Below AFP Sport looks at five things we learned from the Premier League this weekend:

Liverpool's strong challenge for a first title in 29 years seemed set to suffer its first setback at Stamford Bridge courtesy of more Eden Hazard magic for Chelsea. But on a day when Liverpool's famed front three of Mohamed Salah, Roberto Firmino and Sadio Mane failed to fire, Jurgen Klopp was able bring Daniel Sturridge off the bench to score a sensational dipping equaliser from 25 yards a minute from time to preserve the Reds' unbeaten start to the Premier League season.

Sturridge has now scored twice against his former club Chelsea and Paris Saint-Germain in three separate competitions despite limited opportunities this season as he works his way back into contention for a more regular role after three injury-ravaged seasons since Klopp took charge.

Even if he doesn't displace Firmino, Salah or Mane, the former England international is proving a very handy extra option for Klopp to call on to underline the strength in depth now at the German's disposal.

Morever, Sturridge may already have done enough to earn an England recall when Gareth Southgate names his squad for Nations League ties with Croatia and Spain later this week.

Jose Mourinho is desperately searching for answers to Manchester United's stuttering form but some of his decisions during a damaging defeat by West Ham were surprising. Jesse Lingard and Alexis Sanchez were not even in the matchday squad despite their attacking threat.

And Mourinho chose to play Scott McTominay in defence, alongside Chris Smalling and Victor Lindelof. It followed the decision to play Ander Herrera as a makeshift defender earlier this season against Tottenham.

And with the like of former United defender Rio Ferdinad saying "something needs to give" at Old Trafford, there is a sense that Mourinho is struggling for answers and running out of time.

A day after Pep Guardiola said he was now a "more mature" player, England forward Raheem Sterling did his best to live up to the Manchester City manager's words.

Not only did he open the scoring for the champions in a 2-0 win at home to Brighton, turning in Leroy Sane's cross just before the half hour, his precise pass to striker Sergio Aguero also set up City's cliching second goal in the 65th minute.

Signed from Bayer Leverkusen for £19 million ($25 million, 21 million euros) in the close-season, Bernd Leno had hoped to make an immediate impact with Arsenal, but the German goalkeeper has been made to wait for his chance.

That moment arrived after a hamstring injury to Petr Cech in Saturday's 2-0 win over Watford.

Leno then produced a fine save to keep out Troy Deeney and coped well with the visitors' bombardment. If he continues in that vein, former Chelsea star Cech may struggle to regain his place once his injury has healed.

By his prolific standards, Harry Kane's five-match run without a goal for club and country earlier this season amounted to a major drought and the headlines screamed with concern for the Tottenham striker.

After finishing as the World Cup's top scorer during England's run to the semi-finals, Kane was perceived to be fatigued and possibly hampered by injury after some slightly below-par displays in the early weeks of the campaign.

But Tottenham manager Mauricio Pochettino stuck by his man and the goals are flowing again.

Having netted in last weekend's win at Brighton, Kane struck twice as Tottenham eased to a 2-0 win at Huddersfield on Saturday.

Kane's first was a predatory header and the second a clinical penalty, leaving no doubts that he is back on form in time for the crucial Champions League clash with Barcelona next week.