Arsene Wenger's side had surrendered first place after Manchester City's win over Crystal Palace on Saturday, but just 24 hours later the Gunners reclaimed pole position with a hard-fought victory at St James' Park.

Giroud's first goal since November 23 was enough to give Arsenal their second successive win and move them one point ahead of second placed City heading into the new year.

Arsenal, who were without German playmaker Mesut Ozil, took the lead when France forward Giroud bagged his 11th goal of the season with a glancing header from Theo Walcott's free-kick in the 65th minute.

"There is a big satisfaction because we surprised many people," Wenger said. "We played two away games and got six points against West Ham and Newcastle and, as you can see, the team is ready for a fight.

"Ozil has a shoulder problem. I don't think he will be available for Cardiff on Wednesday, maybe after that, we will see."

Chelsea comeback seals third

At Stamford Bridge, Chelsea came from behind to win the weekend's marquee match-up thanks to goals from Eden Hazard and Samuel Eto'o.

Jose Mourinho's third placed team are now two points adrift of Arsenal and one behind City, with Liverpool slipping down to fifth spot.

Liverpool had made a dream start when Martin Skrtel bundled home from close-range after Chelsea failed to clear Phillipe Coutinho's inswinging free-kick.

But Brendan Rodgers' side also took the lead and still lost at Manchester City on Boxing Day, and once again they were unable to hold onto their advantage.

It took the Blues just 14 minutes to equalise as Oscar's shot hit Mamadou Sakho and bounced towards Belgian midfielder Hazard, who seized possession and blasted an unstoppable shot into the top corner of Simon Mignolet's goal.

And Chelsea struck again in the 34th minute when Cameroon striker Samuel Eto'o met Oscar's low cross with a prodded strike that eluded Mignolet's weak attempted save.

Liverpool twice appealed in vain for a penalty when Luis Suarez went down under challenges from John Terry and then Eto'o, and the Reds were unable to avoid a second successive defeat.

"You've seen them given. Eto'o was not even looking at the ball," Rodgers said. "He's been streetwise and cute and was looking to block Luis. But Howard Webb was on the spot and we have to accept it and move on."

Mourinho inevitably disagreed, adding: "I think my experience helps me to see things with another perspective -- when I was Brendan's age I only saw things from one side.

"Lucas on Hazard is the real penalty. If someone has to complain it is us. But we won't because we won."

Everton climb into Champions League places

Earlier, Everton climbed into the top four with a 2-1 win over Southampton at Goodison Park.

Romelu Lukaku's winner meant Roberto Martinez's side moved above Merseyside rivals Liverpool into fourth place.

"Southampton are a very good side and we knew we had to be perfect in our performance. The two goals were of outstanding quality," Martinez said.

Irish defender Seamus Coleman opened the scoring for Everton with a fine strike in the ninth minute.

The Toffees were rocked in the 71st minute when Adam Lallana picked out Gaston Ramirez and the Southampton star advanced before smashing a dipping shot past Everton keeper Joel Robles.

But on-loan Chelsea striker Lukaku struck three minutes later to seal Everton's third win in their last four matches.

Elsewhere, Tim Sherwood celebrated his first victory as Tottenham's permanent manager as Stoke were beaten 3-0 at White Hart Lane.

Sherwood had been frustrated by a 1-1 draw against West Bromwich Albion in his first match since being handed an 18-month contract to replace the sacked Andre Villas-Boas.

But the former Tottenham midfielder, who had overseen a win at Southampton during his brief spell as Spurs' caretaker boss got the first victory of his official reign in emphatic fashion.

The north Londoners took the lead in the 37th minute when Roberto Soldado converted a penalty after Ryan Shawcross blocked Emmanuel Adebayor's acrobatic shot with his arms.

Mousa Dembele added the second in the 65th minute and Aaron Lennon delivered the knockout blow four minutes later.