SUPER-SUB Victor Anichebe came to the rescue for the second successive home game by lifting Albion out of the bottom three with a precious late leveller.
The Baggies looked to be heading for a harsh home defeat against the Barclays Premier League leaders – their first since early December – with Branislav Ivanovic’s first-half stoppage-time strike separating the two sides.
But the never-say-die attitude of Pepe Mel’s men was there for all to see as they produced a stirring second-half comeback.
Anichebe came on in the 74th minute and 13 minutes later planted a header past Petr Cech.
It was the third Hawthorns clash in a row the Baggies have come from behind at half-time to take a point against a top-six side.
And it means they move out of the relegation zone on goal difference from Sunderland, who visit Manchester City tomorrow.
Thievy Bifouma was handed his full Barclays Premier League debut as Mel made four changes to his side – one enforced.
Morgan Amalfitano, Saido Berahino and Steven Reid were also recalled to the Baggies’ starting XI.
Meanwhile, Jose Mourinho made one change as Ramires replaced the benched Frank Lampard.
The visitors applied the early pressure and in the 12th minute Samuel Eto’o cut the ball back for Oscar, who fired a dangerous ball across the box that Gareth McAuley just pipped Ramires to.
The Baggies gradually got into the game and on 20 Berahino slotted the ball through for Thievy to chase but Cech was quick off his line to gather at the striker’s feet.
Moments later, Eto’o deceived Craig Dawson in the box with a sharp turn and delivered a low cross into the six-yard box, where a combination of McAuley and Claudio Yacob smuggled the ball away from Ivanovic at the expense of a corner.
The Albion defence was standing strong and in the 27th minute Willian tried his luck from 25 yards with a fierce strike that flew just past the right-hand angle of post and bar.
Moments later, the hosts caught the Blues on the counter-attack.
Amalfitano beat his former Marseille team-mate Cesar Azpilicueta down the right and crossed to the back post, where Berahino headed the ball back for Thievy in the middle. But the new loan signing chose not to shoot first time from ten yards and eventually teed up Chris Brunt, who fired his 18-yard shot across the face of goal.
Three minutes before the break, Dawson’s clearing header from Oscar’s cross fell at the feet of Willian, who sent a dipping volley just over the bar from 25 yards.
But just as Albion looked to have seen out the first half they conceded a string of corners that eventually led to Chelsea opening the scoring.
The fourth official’s board went up to show a minimum of two added minutes. Just as the game entered the third minute of stoppage time, Willian swung in a corner from the right. David Luiz flicked it on at the near post for Ivanovic, who drilled home from close range with virtually the last kick of the half.
Five minutes into the second half, Willian slid the ball into the path of Eto’o on the right-hand side of the box and the Cameroon star unleashed a fierce 15-yard shot that Foster did well to beat out.
The Blues were fortunate to see the ball land at Willian’s feet from Brunt’s tackle in the 59th minute and he ran at the Baggies defence before seeing his sweet strike well saved by Foster via a deflection from Dawson.
Mel was forced into a change on 63 as Youssouf Mulumbu replaced the injured Yacob.
Two minutes later, McAuley met Brunt’s left-wing corner 15 yards out – but could not direct his header on target.
Mourinho made a change on 69 as Eto’o made way for Torres.
A minute later, Thievy pulled the ball back for Brunt whose right-footed shot was wide of the mark from 12 yards.
The visitors broke swiftly and, although Eden Hazard looked to be off-side, he was allowed to power forward. But the Baggies defended well and eventually restricted Willian to a shot from just inside the box that Foster saved comfortably.
At the other end, Thievy was looking dangerous again and he found Morrison inside the box. The Scotland international should have hit the target but blazed over from 15 yards.
Amalfitano then made way for Anichebe on 73.
Two minutes later, Brunt’s cross landed at Thievy’s feet and his goalbound strike was deflected just wide of the far post by Gary Cahill.
Brunt was himself presented with a glorious chance on 77 as Anichebe flicked on Steven Reid’s right-wing cross, but the Baggies skipper fired wide of the right-hand post from 12 yards.
The Baggies won another corner on 81. Brunt delivered from the right and Dawson climbed highest at the near post – but headed over.
The hosts’ pressure finally told in the 87th minute as Anichebe beat Luiz to Berahino’s delightful left-wing cross and glanced his header in off the far post to equalise.
The 90th minute saw the ball fall kindly for Brunt and he was unfortunate to see his left-foot curler from 25 yards fade wide.
ALBION (4-4-1-1): Foster; Reid, McAuley, Dawson, Ridgewell; Amalfitano (Anichebe 73), Morrison, Yacob (Mulumbu 63), Brunt (c); Berahino; Thievy (Vydra 78). Subs not used: Myhill (gk), Lugano, Dorrans, Gera.
CHELSEA (4-2-3-1): Cech (c); Ivanovic, Cahill, D Luiz, Azpilicueta; Ramires (Salah 89), Matic; Willian, Oscar (Mikel 78), Hazard; Eto’o (Torres 69). Subs not used: Schwarzer (gk), Cole, Lampard, Schurrle.
GOALS: ALBION – Anichebe (87). CHELSEA – Ivanovic (45+3).
BOOKINGS: ALBION – Amalfitano (foul 41), Yacob (persistent fouling 50). CHELSEA – Willian (persistent fouling 67), Ivanovic (dissent 77), Luiz (foul 81).
REFEREE: A Taylor (Cheshire).
ALBION STARMAN: James Morrison.