Ancelotti's men keep up pressure on Manchester United after late winner, with Spurs left to rue refereeing decisions that leave them four points behind fourth place.
Sandro’s 30-yard screamer after twenty minutes gave Spurs the lead, before a goalkeeping howler from Heurelho Gomes allowed Lampard to equalize on the stroke of half-time, despite the ball appearing not to have fully crossed the line.
Substitute Salomon Kalou then grabbed his thirteenth goal of the season two minutes from time to secure the three points and ensure the title race is still alive.
The win leaves Ancelotti’s men just three points behind league leaders Manchester United who they play next weekend, whilst Tottenham remain four points adrift of fourth place Manchester City who have a game in hand and the momentum in the race for Champions League qualification.
Chelsea reverted to a 4-4-2 formation ahead of the game to accommodate both Drogba and Torres, whilst Spurs fielded a strong starting XI with Bale recovering from injury and Lennon recalled to first team action.
The home side made the livelier start, with Drogba’s 30-yard free kick crashing off the cross bar, before Malouda easily cut inside Kaboul on the left-hand side only to see his shot from the edge of the box saved by Gomes.
Yet with Spurs first effort on target, Sandro lashed a shot from 30-yards into the top left hand corner of Cech’s goal after just 19 minutes, having latched on to a superb Van der Vaart reverse pass.
The Brazilian’s effort did not earn the reprieve of his manager though, with Redknapp eager to remind the midfielder of his defensive duties.
Chelsea looked to gain a quick equalizer, with Essien forcing Gomes to concede the corner from his header, whilst Torres failed to convert a Drogba flick-on from the resulting kick, with the Spaniards headed effort sailing over the bar of an open goalmouth.
Ancelotti’s men seemingly ran out of attacking steam towards the end of the half, with Ivanovic and Cole’s forward runs both failing to find Drogba and Lampard respectively.
Yet Lampard took advantage of some suspect goalkeeping and refereeing to level just before half-time. The England midfielders dipping shot from 25-yards slipped through the legs of Gomes, only for TV replays to show the ball had not in fact crossed the line.
Chelsea’s early second half penalty claims were waved away, before Drogba’s 25-yard effort stung the gloves of Gomes, with the Ivorian also providing a number of well-placed deliveries into the box.
Fernando Torres was replaced by Salomon Kalou with half an hour to play, with Drogba almost instantaneously justifying his manager’s decision seconds later, only for his free-kick to be suspectly parried away by Gomes.
Jermain Defoe livened up the Spurs forward line as he looked to take the game to Chelsea, taking the place of Pavulychenko who had looked laboured throughout, before the home sides penalty claims were again dismissed by the official after Kaboul appeared to have bundled Malouda in the box.
The Blues were unlucky not to grab a winner with 15 minutes to play, after Lampard fired an effort just over from 20-yards after a superb lay-off from Drogba, whilst substitute Nicolas Anelka failed to make the most of space in the box as he miscontrolled from Kalou’s through ball.
Chelsea’s best chances seemed to have been scuppered by John Terry six minutes from time, after the captain failed to connect properly with Drogba’s low cross from a free-kick.
Yet with two minutes remaining Kalou latched onto a rebounded Drogba effort and fired in the winner from 6-yards, despite appearing to be off-side.