Crystal Palace breathed new life into the title race with a shock win while a crucial victory for Hull stepped up the frantic race to avoid the relegation zone.
Here, Press Association Sport looks at five things we learned from the latest round of fixtures.
DON'T CONTE ON IT
Chelsea's shock loss to Palace at Stamford Bridge, coupled with a workmanlike win for Tottenham at Burnley, can hardly be said to have blown the title race wide open - Conte's men remain rock-solid favourites with a seven-point lead at the top. But it did raise the prospect of a squeakier run-in than expected, with Chelsea having to face both Manchester City and Manchester United before the end of the month. Mauricio Pochettino's men can set their sights high secure in the knowledge that a top-four slot is surely now all but assured.
Despite Manchester United's improved form, Jose Mourinho still cuts a thoroughly miserable figure at Old Trafford. His testy response to a perfectly reasonable question from a BBC interviewer in the wake of United's frustrating goalless draw with West Brom underlined the pressure the Portuguese is finding himself under as he seeks - and singularly fails to find - the spark which contemporaries such as Conte and Pochettino have located this season. Blaming visiting clubs for relentless negativity is to make a botch-job of papering over his own side's obvious limitations.
Talking of relentless negativity, David Moyes has been given a remarkably easy ride this season as his Sunderland side slide towards the drop. The rock-bottom Black Cats remain the only side in the bottom five not to replace their manager this season. But perhaps Saturday's abject defeat at Watford was to be expected given the low expectations Moyes himself foisted on his side this season - from bemoaning transfer market policy to greeting his new boys in the January transfer window by publicly stating he did not expect them to make much difference to his side's survival fight.
It was easy to understand Ronald Koeman's frustrations after a calamitous international break saw injuries to Seamus Coleman, James McCarthy and Ramiro Funes Mori. All of which made the Everton manager's comments after his side's derby loss to Liverpool all the more surprising. Koeman put two over-the-top tackles from Ross Barkley down to the over-enthusiasm of "local boys" on such a fiery occasion, and did nothing to diffuse the macho culture which so blighted Ireland's clash with Wales by reminding interviewers football is "a men's game".
GUNNERS STILL HAVE FIREPOWER
Given their rotten recent run of results and the constant clamour from a section of supporters to get 'Wenger Out', Arsenal did not go into their showdown with Manchester City full of confidence. Indeed they went behind early on, vindicating the detractors, but the Gunners showed grit to cancel out Leroy Sane's opener with a Theo Walcott goal just before the break. Sergio Aguero's rapid reply might have fractured a more fragile Arsenal side in weeks gone by, but Arsene Wenger's men rallied impressively to grab a share of the points through Shkodran Mustafi. They will have easier games - can they fight their way up the table?