Danny Welbeck came off the bench to score a stunning stoppage-time equaliser as Albion deservedly held title-chasing Chelsea at Stamford Bridge.
Welbeck rose to head Marc Cucurella’s cross into the bottom corner before celebrating in front of thousands of jubilant Albion fans in the corner.
It was no more than the visitors deserved, having dominated for long spells after Romelu Lukaku’s controversial opener for Chelsea.
The Belgian striker’s first-half goal was allowed to stand despite vehement Albion protests that he had fouled Neal Maupay when he headed in Mason Mount’s corner.
Albion’s record of never scoring in a league game at Stamford Bridge looked as if it would extend to seven games. Adam Lallana, Tariq Lamptey, Yves Bissouma, Alexis Mac Allister and Maupay all went close. It looked like being one of those nights, but then Welbeck showed his quality and Albion had their reward.
Graham Potter had made three changes to the side that earned Sunday’s welcome win over Brentford with Adam Webster, Enock Mwepu and the injured Leandro Trossard replaced by Joel Veltman, Bissouma and Solly March,
Nearly two years after leaving Chelsea, Lamptey was determined to put on a show and had the game’s first chance when Joel Veltman’s pass found him in space. He cut past Reece James but then curled a low shot with his weaker left foot well wide.
Chelsea knew avoiding defeat would lift them into second place and they began to up the tempo. Cesar Azpilicueta stabbed a shot against the post when Mount’s corner dropped to him 12 yards out before Lukaku’s clever pass teed up Mount for a shot which Robert Sanchez parried at his near post.
Chelsea were forced into a change when James limped off but they took the lead in the 28th minute when Lukaku shrugged off Maupay to plant a powerful header from Mount’s corner into the bottom corner. Albion appealed that Maupay had been fouled but referee Mike Dean allowed the goal to stand.
Albion responded positively and dominated for 15 minutes before half-time. Bissouma had control of the central areas and tested Edouard Mendy from 25 yards before the keeper had to push away Adam Lallana’s left-footed effort from inside the D.
Lallana dragged another effort from outside the box wide, Antonio Rudiger was booked for a hefty lunge on Lamptey, who was relishing the room down the right, and Mendy was called into action again just before the break when he held Mac Allister’s shot. The visitors would have considered themselves unfortunate to be trailing at the break.
They were on the front foot again at the start of the second half. Jakub Moder diverted Lallana’s clever ball into the box onto the top of the bar with Mendy stretching before Bissouma turned over possession yet again and tested Mendy from distance and this time the Frenchman flipped the ball over at full stretch.
Albion were on top, but they should have been punished in the 56th minute when Lukaku’s pass sent Callum Hudson-Odoi sprinting away. He tried to find the unmarked Mount but Veltman, the only Albion outfield player in the box, got in a crucial block.
Back came the visitors and Maupay rattled a low drive just past the post before Mateo Kovacic became the second Chelsea player to be cautioned for fouling Lamptey. Albion were knocking at the door. Mac Allister rounded Mendy and picked out Maupay whose shot was blocked, Lamptey fired wide then Lallana had his head in his hands after Solly March found him unmarked 12 yards out but he lifted his shot over the target.
Welbeck was introduced with ten minutes to go but Chelsea seemed to have found a second wind. Veltman and Burn made crucial blocks inside the box to deny Lukaku and substitute N’Golo Kante.
Could Albion create one more chance? Yes they could. In the first minute of stoppage time Marc Cucurella hung up a tempting cross from the left and Welbeck rose between two defenders to head home. A happy end to 2021.
Albion: Sanchez, Lamptey (Mwepu 65), Veltman, Burn, Cucurella, Bissouma, Lallana, March, Moder (Alzate 88), Mac Allister (Welbeck 80), Maupay.
Subs: Steele, Webster, Gross, Duffy, Richards, Ferguson.