Manchester City suffered their first defeat under manager Pep Guardiola as Tottenham Hotspur underlined their Premier League title credentials with a 2-0 win at White Hart Lane on Sunday.
Victory saw Spurs move to within a point of leaders City.
And later on Sunday, Arsenal -- Spurs' north London rivals -- won 1-0 away to Burnley thanks to Laurent Koscielny's disputed winner deep into stoppage time as Arsene Wenger's men closed to within two points of top spot.
Meanwhile reigning champions Leicester City were held to a goalless draw by Southampton while Manchester United endured a frustrating 1-1 draw at home to Stoke City.
Here are five things we learned this weekend
Slick Spurs are title contenders
With Jose Mourinho arriving at Manchester United, Manchester City snaring Pep Guardiola, Antonio Conte joining Chelsea and big-money signings at Arsenal and Liverpool, there was little talk of the challenge Tottenham Hotspur might pose in the Premier League prior to the start of the season. Spurs were Leicester City's main challengers last season, only to fade away and finish third, but there was a feeling that they, like Leicester, would end up as collateral damage in the arms race between the division's traditional superpowers.
Tottenham produced a sublime display to beat City 2-0 on Sunday, condemning Guardiola to his first defeat in the job. Guardiola's men could not handle Spurs' asphyxiating high press -- typified by the industry of Son Heung-Min, goal-scorer Dele Alli and Victor Wanyama -- and Mauricio Pochettino's side woud have won more comfortably had Erik Lamela not squandered a second-half penalty. Spurs now possess the last unbeaten record in the division and with City just a slender point above them, the summit is within reach.
Conte stiffens Chelsea defence
Three was the magic number for Antonio Conte as the Chelsea manager was rewarded for changing his defensive tactics in a 2-0 win over Hull on Saturday. Shocked by the sloppy displays given by his back four this season -- an alarming sequence that culminated in last weekend's 3-0 defeat at Arsenal -- Conte opted to switch to a system that deployed three centre backs at the KCOM Stadium.
Chelsea manager Antonio Conte: "We gave a good performance with the right intensity & pressure. I like it when they play in this way." pic.twitter.com/1wvBd8JL0t— Premier League (@premierleague) October 1, 2016
David Luiz, Gary Cahill and Cesar Azpilicueta made up the reconfigured back three and the trio quickly adapted to Conte's switch as they kept only Chelsea's second clean-sheet of the season. Conte is something of an expert in playing with a back three after using the formation during his spells as Juventus and Italy coach. The Italian is likely to stick with it after seeing Chelsea halt their run of nine goals conceded in four games.
Arsenal have won five successive Premier League games for the first time since October 2015 pic.twitter.com/eioJgD0Y6I— Premier League (@premierleague) October 3, 2016
A match away to Burnley had all the hallmarks of being the kind of fixture that has prevented Arsenal winning the Premier League title for more than a decade. But while their usual elegance was missing, they still managed to win 1-0 thanks to Laurent Koscielny's goal in the third minute of stoppage time that might have been ruled out for both handball and offside. Sometimes it really is better to be lucky than good.
Foxes on the run
Frustrated by Southampton in a goalless home draw on Sunday, Leicester are discovering the perils of defending a title. Claudio Ranieri's side became the most unexpected English champions ever when they lifted the title last season, but they have won only two of their seven league matches this term as reality starts to bite. The pre-season departure of France midfielder N'Golo Kante to Chelsea robbed Leicester of their driving force and Ranieri has so far failed to come up with a successful Plan B.
James Milner has netted 4️⃣ spot kicks so far this season - more than any TEAM! pic.twitter.com/Cyc3RX9nZV— Premier League (@premierleague) October 1, 2016
Jurgen Klopp's Liverpool have played some scintillating football this season, crushing champions Leicester 4-1, putting five goals past Hull City and winning 4-3 at Arsenal on the opening day. But they came unstuck in unexpected fashion in their second game at Burnley, losing 2-0 despite dominating the match. A similar fate appeared to await them on Saturday after they fell behind to an eighth-minute Leroy Fer goal at struggling Swansea City and saw Adam Lallana hobble off with a groin injury. But Klopp's men dug deep, equalising through Roberto Firmino's header and eventually prevailing courtesy of a late James Milner penalty. It was not pretty, and Klopp was furious about his team's sloppy start, but it might just have been the stuff of champions.