What we learnt from the Premier League

Manchester United's mood for the festive season was also lifted by Ole Gunnar Solskjaer making an instant impact, as for the first time in five years United scored five goals in the league by thrashing Cardiff 5-1.

United are now just eight points off the top four and the race for Champions League places tightened thanks to Chelsea's first home defeat under Maurizio Sarri to Leicester and Arsenal's routine win over Burnley.

Tottenham are now five points clear of their London rivals and just six off the top in third as Mauricio Pochettino's side outclassed Everton in a 6-2 win at Goodison Park.

Here, AFP Sports looks at five things we learned from the Premier League weekend:

Fernandinho City's unsung star

City have coped admirably without Kevin De Bruyne for almost the entire campaign and even David Silva in recent weeks, but were shocked by Crystal Palace when forced to cope without Fernandinho in midfield for the first time in the league this season.

There is little even the Brazilian could have done to stop Andros Townsend's stunning volley that put Palace into a 2-1 lead against the run of play, but in and out of possession, Fernandinho makes City tick.

Unfortunately for the champions, he is also the one player in their squad without a natural replacement.

With John Stones pushed into an unfamiliar holding midfield role, City didn't control the Palace counter-attack.

Now chasing in the title race, City need the 33-year-old back quickly for what could be a decisive three-game run starting away at Leicester and Southampton before they host Liverpool on January 3.

Solskjaer makes Man Utd smile again

The contrast between the sombre mood of Jose Mourinho's final days as Manchester United manager and the joy at the final whistle as Solskjaer and his players basked in the adulation of the travelling support in the Welsh capital said it all.

For the first time in a long time United's fans had witnessed the sort of fast, attack-minded and clinical football that Solskjaer was so often involved in as a player at Old Trafford.

The Norwegian insisted the result was all down to having "good players", but with the same squad Mourinho's sullen nature failed to summon the same response.

"He always has a smile on his face and I think that can reflect down on to the team," said United captain Ashley Young of Solskjaer's impact.

The year of Van Dijk

A year ago Liverpool had just conceded three goals in five minutes during a thrilling 3-3 draw at Arsenal that encapsulated the strengths and flaws of Jurgen Klopp's side.

Five days later Virgil van Dijk was signed for a world record £75 million ($94.5 million) and the days of defensive lapses undermining a title challenge appear gone. In 18 games, Liverpool have conceded just seven goals.

The giant Dutchman scored just his second goal for the club in a 2-0 win at Wolves on Friday night, but it was another commanding display at the back that won him man-of-the-match.

Chelsea fail to respond

For the third time in six matches, Chelsea paid the price for a lack of focus and cutting edge as they crashed to a surprise 1-0 defeat against Leicester.

Sarri questioned his players' "mental strength" and admitted he had no explanation for their "confusion" after Jamie Vardy put Leicester ahead in the 51st minute.

"Yes it concerns me," said Sarri. "You can go 1-0 down, the important thing is how you are able to react."

Aubameyang's fast start

Pierre-Emerick Aubameyang has gone slightly under the radar since joining Arsenal in January, seeing the headlines grabbed by striking rivals Mohamed Salah, Harry Kane and Sergio Aguero.

But two goals against Burnley on Saturday upped his tally to 12 in the Premier League this season -- one clear of Liverpool's in-form Salah, and Kane.

Even more impressively, Aubameyang's 22 goals in his 31 Premier League appearances for Arsenal mean he has scored five more than any other player for the club at the same stage. Arsenal legend Thierry Henry is next on 17.