Five things we learnt in the PL

Premier League leaders Manchester City maintained their perfect start under Pep Guardiola as Manchester United returned to winning ways against champions Leicester City.

Here are five things we learnt this weekend.

NO ROONEY, NO PROBLEM FOR MAN UNITED

The Manchester United team sheet for Saturday's home game with Leicester City caused a stir after manager Jose Mourinho elected to drop captain Wayne Rooney, who has been struggling for form. The outcome did not make pleasant viewing for United's number 10, who looked on from the bench as his team-mates produced their most convincing display of the season with a classy 4-1 victory over the champions.

Juan Mata slotted in for Rooney in the number 10 role and proved a far livelier presence, slamming home United's second goal after a delightful team move involving a chipped pass from Paul Pogba and a volleyed lay-off from Jesse Lingard. Pogba seemed to relish the greater space afforded him by Rooney's absence and turned in his best United performance to date, opening his account for the club with a 42nd-minute header. With Marcus Rashford and Zlatan Ibrahimovic also impressing in attack and Ander Herrera setting the tempo in midfield, Rooney has a fight on his hands to get his place back.

CONTE HAS PRESSING ISSUES IN DEFENCE

Chelsea produced a defensive horror show in their 3-0 defeat at Arsenal as Arsene Wenger's men ended a six-game league scoring drought against their London rivals with three goals in the first 40 minutes. Chelsea's back four seemed uncomfortable with manager Antonio Conte's high defensive line and struggled to play the ball through Arsenal's press.

Gary Cahill was particularly poor, gifting the ball to Alexis Sanchez prior to Arsenal's first goal, and right-back Branislav Ivanovic endured a torrid evening. Captain John Terry and young centre-back Kurt Zouma are expected to return to fitness next month and having seen his team concede nine goals in their last four league and cup outings, Conte will be eager to get them back.

AGUERO STILL THEN MAN

As if anyone was in any doubt, Sergio Aguero took just nine minutes to underline why he remains Manchester City's most valuable player.

Returning from a three-match suspension for elbowing West Ham’s Winston Reid, Aguero was a constant menace for the Swansea defence at the Liberty Stadium on Saturday.

He opened the scoring in the ninth minute with a typically predatory finish, turning inside the penalty area and driving his shot under Swansea goalkeeper Lukasz Fabianski.

After Swansea equalised,Aguero scored again, cheekily sending Fabianski the wrong way with a clipped penalty in the 65th minute.

Aguero’s 11th goal in all competitions this season ensured City would remain on top of the Premier League and extended Guardiola’s perfect start.

REDS UNDERLINE TITLE BID

Liverpool have not been crowned champions of England since 1990 and a match against Hull was exactly the kind of fixture that has often proved their undoing in recent title bids. Liverpool manager Jurgen Klopp had written in his programme notes that describing Hull as "just hard to beat" was doing them a disservice but that didn't stop his side winning 5-1, with playmaker Philipp Coutinho impressive again.

HAMMERS' DEFENSIVE WOES

Just when Slaven Bilic thought things couldn’t get any worse for West Ham’s creaky defence, the Croatian coach had to watch Southampton run his back-four ragged in Sunday’s 3-0 victory for the visitors at the London Stadium.

After a promising first season in charge of the Hammers, Bilic appears stuck in a recurring nightmare this term as every Premier League match brings a fresh set of indignities for his beleaguered rearguard.

Conceding three at table-topping Manchester City is understandable, but in the following two matches, West Ham shipped four goals in defeats against the less star-studded attacks of Watford and West Bromwich Albion.

Charlie Austin opened the scoring for Southampton before half-time and further goals from Dusan Tadic and James Ward-Prowse left West Ham captain Mark Noble admitting his side could easily have lost by six.