Mikel Arteta earned his first win as Arsenal manager with a 2-0 victory over Manchester United in the English Premier League at Emirates Stadium on New Year's Day.
Nicolas Pepe swept in the opener on eight minutes and Sokratis Papastathopoulos grabbed the second in the 42nd after United goalkeeper David De Gea parried Alexandre Lacazette's header.
Man-of-the-match David Luiz backed Arteta to be the right man to turn around the struggling Gunners.
"I think Mikel is a great coach. He knows football. I believe in this philosophy and he can improve every single player. In life, when you are happy the results can be totally different," the Brazilian defender told BT Sport.
After collecting one point from his first two games since replacing Unai Emery, Arteta secured Arsenal's first home win in the league in three months.
"The feeling is incredible. Right from the start I could feel (the enthusiasm from the crowd). I could feel a different atmosphere and thank you to them. These players will play much better with the support behind them and energy. Hopefully we gave them something to be proud of today.
While Arsenal climbed to 10th in the standings, United's first defeat of the campaign to a fellow member of the Premier League's 'big six' leaves them five points off the Champions League places.
Manager Ole Gunnar Solskjaer admitted the hosts were the better team in the first half and also hinted he may dip into the transfer market this month.
"It was a game between two teams with loads of quality, which Arsenal showed more than us in the first half and they won the game through that ... but we will bounce back again," the 46-year-old Norwegian said.
"You can see the squad and sometimes you think 'Yeah, one or two additions would do nicely', because we are building towards something and it just depends on what we think is right for us and will be available."
Leicester City cut Liverpool's lead at the top temporarily to 10 points after a 3-0 win at Newcastle.
Ayoze Perez, James Maddison and Hamza Choudhury scored the goals as Brendan Rodgers' side continued their fine form.
"The players had great fluency. We pressed really hard. We worked them in the second half, stretched the game and it led to the third goal," said Rodgers, who rested striker Jamie Vardy.
Champions Manchester City are one point behind the Foxes after Gabriel Jesus scored twice in the 2-1 win at Everton.
"I was absolutely delighted about the performance. Normally teams in this situation (so far behind, almost conceding the title) give up," City manager Pep Guardiola said.
West Ham beat Bournemouth 4-0 in David Moyes' first match back in charge to move out of the bottom three while bottom side Norwich are seven points adrift after a 1-1 draw with Crystal Palace.
Aston Villa won 2-1 at Burnley as Wesley and Jack Grealish scored to earn a rare away win.
Watford claimed a 2-1 win over Wolves thanks to goals from Gerard Deulofeu and Abdoulaye Doucoure, but remain in the bottom three.
Alireza Jahanbakhsh scored a stunning overhead kick as Socceroos Aaron Mooy and Mat Ryan's Brighton drew 1-1 with fourth-placed Chelsea, lifting the home side up to 14th.
Tottenham's top-four hopes suffered another blow with Danny Ings scoring his 20th of the season in Southampton's home win.
League leaders Liverpool host eighth-placed Sheffield United on Thursday.
Australian Associated Press