Chelsea missed the chance to go four points clear at the top after they were held 1-1 away at Premier League strugglers West Bromwich Albion – who moved out of the relegation zone.
Branislav Ivanovic opened the scoring at The Hawthorns, but the Blues were unable to build on that advantage and saw Victor Anichebe step off the bench to restore parity.
Chelsea are now two points ahead of Arsenal and three clear of Manchester City at the top of the Premier League table, with the latter sides set to play their game in hand on Wednesday, against
Manchester United and Sunderland, respectively.
Thievy Bifouma, who marked his Baggies debut at Crystal Palace on Saturday with a goal less than a minute after coming on, was was rewarded with a first start, one of four changes made by Pepe Mel.
Jose Mourinho made just one change from the 3-0 win over Newcastle on Saturday, replacing Frank Lampard with Ramires, who had been rested for that win over the Geordies. Terry was still unavailable through injury.
There was little to unduly concern either back line in the opening 20 minutes, although the Blues had established a controlled hold on possession.
In the 22nd minute, Willian found Samuel Eto’o inside the area and his cutback was scrambled away from the onrushing Ivanovic by a combination of Gareth McAuley and goalkeeper Ben Foster.
West Brom grew impressively into the game and Chris Brunt fizzed a low drive wide after Thievy failed to control Berahino’s knockdown.
A succession of Chelsea corners came to nothing until their final set-piece of the half – in the third minute of stoppage time – was touched on by David Luiz and his defensive colleague, Ivanovic, slammed home unmarked.
The second half saw West Brom and Chelsea muster up 12 and 15 shots respectively but it was a game that lacked clear cut opportunities for either side to tuck away.
Willian came the closest to extending Chelsea’s lead, but the Brazilian found Ben Foster in fine form.
As the half wore on the home side finally found some impetus up front and began to create opportunities, with James Morrison firing wide, Thievy flashing a shot through the six-yard box and Chris Brunt hammering a half-volley past the post.
Anichebe was introduced with 17 minutes remaining in an effort to provide greater cutting thrust, and he delivered in dramatic fashion after getting in front of David Luiz to turn in a pinpoint cross from Berahino.
Chelsea (4-2-3-1): Cech; Ivanovic, Cahill, David Luiz, Azpilicueta; Ramires (Salah 88), Matic; Willian , Oscar ( Mikel 78), Hazard; Eto’o (Torres 68).
Booked Willian 66, Ivanovic 75, David Luiz 80.
West Bromwich Albion (4-3-3): Foster; Reid, McAuley, Dawson, Ridgewell; Morrison, Yacob (Mulumbu 62), Brunt (c); Amalfitano (Anichebe 72), Berahino, Thievy (Vydra 77).
Booked Amalfitano 41, Yacob 49
Referee Anthony Taylor