Diego Costa again starred for Chelsea as his hat-trick helped the Blues beat Swansea City 4-2 and consolidate their position at the top of the Premier League.
Apart from the former Atletico Madrid striker, Loic Remy also recorded his name on the scoresheet, along with John Terry (own goal) and Jonjo Shelvey.
The game started with the Swans breaking the deadlock in the 11th minute through a Terry own-goal.
A good move from the visitors saw Ki Sung-yeung feed the ball to Neil Taylor, who sent a low cross into the box that Terry could only divert into his own net.
The Welsh side threatened to double their lead in the 21st minute when Sigurdsson picked up Wayne Routledge near the edge of the box. The midfielder took a shy on goal but his curling effort was narrowly wide of the post.
Chelsea, who were forced on the back foot in the opening period of the game, slowly started finding their rhythm as Andre Schurrle tested Lukasz Fabianski with a free-kick in the 33rd minute and Ivanovic's cross was narrowly headed over by Oscar a couple of minutes later.
The Blues' efforts soon bore fruit as Costa powered home a header from a corner and grabbed the leveller just before the stroke of halftime.
After the break, the Brazil-born striker fired the Blues ahead as he smashed an effort into the roof of the net following a good assist from Fabregas.
Despite the Blues' dominance Gary Monk's side refused to lay down their arms and they nearly caught the Blues out of position in the 65th minute. Bafetimbi Gomis, after breaking away from the Chelsea defence, tried to chip one over an on rushing Thibaut Courtois, but his effort was just wide of the target.
The Swans were soon punished for their miss as Costa grabbed his hat-trick in the 76th minute. The Spain striker fired from close range after latching on to a meek effort from Ramires.
Loic Remy, who came in as a substitute for Costa in the 72nd minute, also joined the party as he found the net on his debut for Chelsea. The Frenchman tucked the ball home from the left side of the six-yard box after receiving a pass from Oscar.
Finally the Swans were able to pull a goal back through Shelvey, who fired from close range after receiving a good pass from Wilfred Bony.