Olivier Giroud took advantage of a huge goalkeeping blunder to score a brace as Arsenal moved four points clear at the top of the English Premier League with a 2-0 win over surprise package Southampton.
The Gunners bounced back from their defeat against Manchester United and took advantage of second-place Liverpool's 3-3 draw at Everton to increase their lead to 28 points.
Arsene Wenger's team took a cautious start but gradually stamped their authority on the match and opened the scoring in the 22nd minute after Southampton goalkeeper Artur Boruc gifted a bizarre goal, losing the ball to Giroud in his box.
The former Montpellier striker then doubled the Gunners' lead from the penalty spot, sending Boruc the wrong way after Per Mertesacker was had his jersey pulled in the box.
"I'm very happy because we were against a good team and they showed why they made good results before,'' Wenger said after giving Southampton their second league loss this season.
Lampard nets double
| Chelsea's Frank Lampard, centre, celebrates scoring a penalty against West Ham United in the London derby [AFP]
Surrounded and supported by ball-playing midfielders half his size, Giroud has now scored 10 goals in all competitions for Arsenal this season and Wenger said his spirits had been lifted by France's qualification for the World Cup on Tuesday.
Liverpool are second on 24 points after a pulsating Merseyside derby ended 3-3 at Goodison Park as Daniel Sturridge scored in the 89th minute for the visitors after Everton had twice come from behind to lead 3-2.
On-loan Belgium striker Romelu Lukaku thought he had won it when he headed his second of the match to put Everton ahead after 82 minutes, only for substitute Sturridge to snatch a point for the visitors.
"That is the best experience I've ever had in club football," said Lukaku, echoing the feelings of those lucky enough to watch the pulsating match.
It was end to end stuff from the start as Philippe Coutinho scrambled Liverpool ahead after five minutes, Kevin Mirallas - lucky to escape a red card for a wild challenge on Luis Suarez - equalised two minutes later and a Suarez free kick put Liverpool ahead at the break
Lukaku's second-half double looked to have earned Everton only their second win in 14 derbies until Sturridge levelled.
The day's London derby was much more Straightforward as Frank Lampard scored twice in Chelsea's comfortable 3-0 win at his old club West Ham United which also took them to 24 points.
Chelsea, with only one point from their last two matches, were making little progress against West Ham in the opening 20 minutes until Jussi Jaaskelainen brought down Oscar and Lampard smashed in the penalty
New manager confirmed
Neat work by Eden Hazard set up Oscar to calmly finish for the second after 34 minutes and the match was effectively over.
Struggling West Ham fought hard after the break but were finished off eight minutes from time when Lampard swept in his second from the edge of the box.
Elsewhere in the Premier League, Newcastle United continued their great run as they followed up victories over Chelsea and Tottenham Hotspur with a 2-1 home win over Norwich City to move to 20 points alongside champions Manchester United and Spurs, who are both in action on Sunday at Cardiff City and Manchester City respectively.
Chelsea, in fourth place on 21 points, play at lowly West Ham United later on Saturday and can move above Southampton who remain in third spot on 22 points after their defeat.
Stoke City beat 10-man Sunderland 2-0, after the visitors had defender Wes Brown sent off in the first half, while Swansea City won 2-1 at struggling Fulham whoa re in the drop zone.
Crystal Palace climbed off the bottom and above Sunderland as they collected their first away points of the season with a 1-0 victory at Hull City, with Tony Pulis confirmed as their new manager earlier on Saturday, watching from the stands.