5 things we learned from the Premier League this weekend
Chelsea went top of the Premier League, there was a shock goal hero for Manchester City and two more familiar scorers for Tottenham and Sunderland.
Here, Press Association Sport looks at the things we learned from this weekend's Premier League action.
Blues hit the top
Liverpool's goalless draw at Southampton left the door open for Chelsea to go top, and Diego Costa pushed his side through it. The Spaniard is surely the most in-form striker in the Premier League, and his 10th goal of the season was enough to sink Middlesbrough. Costa was quickest to react at a half-cleared corner, stabbing home past Victor Valdes from close range just before half-time. Antonio Conte's side look like they mean business in the title race.
When will it end?
So Arsene Wenger has still never beaten Jose Mourinho in a Premier League match. But he may feel his fortunes are changing after Arsenal snatched a 1-1 draw at Manchester United, Oliver Giroud nodding in a cross from fellow sub Alex Oxlade-Chamberlain to cancel out Juan Mata's opener. Instead it was Mourinho bemoaning his luck afterwards, saying "I feel sorry for the players because we feel like a defeat and, for sure, Arsenal is feeling like a victory".
Yaya can Pep up City
Surprise of the weekend had to be Pep Guardiola's decision to bring Yaya Toure in from the cold at Crystal Palace. The 33-year-old has finally resolved the "misunderstandings" which led to him being frozen out by the City boss and capped his first appearance of the season with both goals in their 2-1 win. It was only City's third victory in 10 attempts and even if Toure remains down the pecking order he could yet play a pivotal role in their title bid.
Jermain Defoe may be 34 but his appetite for goals remains undiminished. The master finisher scored his 150th Premier League goal as Sunderland comfortably beat Hull 3-0 to climb off the foot of the table. Defoe's trademark darting run and low shot made him only the eighth player in Premier League history to bring up the milestone, and set rejuvenated Sunderland on their way to consecutive top-flight wins for the first time since May.
That's what Tottenham boss Mauricio Pochettino proclaimed after Harry Kane's late heroics sank West Ham. Spurs' unbeaten record looked like it was about to come to an end with the Hammers leading 2-1 with two minutes to go. But Kane, fit again after seven weeks out with an ankle injury, equalised with a classic poacher's finish and then tucked in an ice-cool penalty in stoppage time. The double took his tally in London derbies to 18 in 22 matches.