London - Chelsea went marching on at the top but Liverpool lost ground and Pep Guardiola is facing his first real test as Manchester City boss as they crashed 4-2 at champions Leicester.
Here is a look at five things we learnt from the weekend Premier League matches:
"Jamie Vardy's having a party!" became a familiar chant at the King Power Stadium last season as the rough-cut striker inspired Leicester City to their fairytale title triumph. His difficulties in front of goal this season had come to symbolise the club's post-title hangover, the England striker going 16 games without a goal as Claudio Ranieri's side slithered towards the relegation zone.
But he blew off the cobwebs in style in a rain-lashed evening game against Manchester City on Saturday, firing Leicester to victory with his first hat-trick since his non-league days.
All three goals were taken in the clinical fashion that was Vardy's calling card last season, with the second - teed up by Riyad Mahrez's gossamer-soft pass - a particular treat.
The third stemmed from a blind back-pass by City centre-back John Stones, whose blunder encapsulated the struggles of a City defence that has registered just one clean sheet in 17 matches.
Guardiola once again opted for a bold attacking configuration, only to be left scratching his head. "I try to control games," he said. "Here (in England) I cannot do that. I have to analyse why."
2. ARSENAL SHOW TITLE METTLE
Trailing to Charlie Adam's 29th minute penalty, Arsenal faced a potentially defining moment in their Premier League campaign, and to Arsene Wenger's delight his players rose to the challenge.
Suffering a first league defeat since the opening weekend of the season would have been a significant blow to Arsenal's hopes of winning the title for the first time since 2004. It was the sort of scenario that has caused Arsenal to collapse many times in recent years, but this season looks a little different.
They equalised in the 42nd minute when Theo Walcott bagged his 100th club goal and took the lead four minutes after half-time through Mesut Ozil's header before youngster Alex Iwobi sealed the points in the 75th minute to extend Arsenal's unbeaten league run to 14 matches and keep the pressure on title rivals Chelsea.
Faced with an obdurate opponent in Tony Pulis's well-drilled West Bromwich Albion, Chelsea boss Antonio Conte showed his flexibility by ditching his preferred three-man defensive formation and his gamble paid immediate dividends.
Conte's side had been frustrated for over an hour at Stamford Bridge on Sunday when the Italian sent on Willian and Cesc Fabregas in a switch to a 4-4-2 system.
The move gave Chelsea more attacking options and in the 76th minute a Fabregas pass induced a mistake from Albion defender Gareth McAuley that was punished by Diego Costa's clinical finish.
Chelsea's ninth successive league win reopened a three-point lead at the top and underlined that Conte is more than a one-trick pony.
Having spent the best part of three months as a virtual spectator following his transfer from Borussia Dortmund, Henrikh Mkhitaryan has belatedly emerged as Manchester United's go-to attacking player.
After a pair of assists in a 4-1 League Cup win over West Ham United and a first United goal against Zorya Luhansk, he settled Sunday's game against Tottenham Hotspur with a burst from deep and an emphatic shot.
The Armenian playmaker was stretchered off after injuring his ankle, but to sighs of relief all round Old Trafford, manager Jose Mourinho said it was not serious.
United have struggled for goals in the league, scoring eight in their last nine games, but in the jet-heeled Mkhitaryan they possess a player capable of bridging the gap that had existed between the team's midfield and lone striker Zlatan Ibrahimovic.
Mourinho had publicly questioned whether Mkhitaryan was physically ready for the rigours of the Premier League, but after the 1-0 win over Spurs, he held up the 27-year-old's defensive industry as an example.
For a second successive match Liverpool's dazzling attack wasn't sufficient as their defence was again exposed as the Achilles' heel with struggling West Ham taking a point in a 2-2 draw.
The yield of just one point from the last six could prove very costly come the end of the season.
German goalkeeper Loris Karius will again be under the spotlight, especially with Dimitri Payet's freekick, but the back four do not inspire confidence and January could see action at Anfield in the transfer market.
All images: Getty