Brighton inflicted a major blow on Chelsea's Premier League title hopes as substitute Danny Welbeck's stoppage-time header secured a 1-1 draw for the Seagulls in a pulsating encounter at Stamford Bridge
Chelsea were on the brink of victory having survived a barrage of Brighton pressure following Romelu Lukaku's first-half opener (26), but Welbeck's dramatic leveller, nodded in from Marc Cucurella's cross (90+1), left them stunned and secured a deserved point for Graham Potter's side
The result is a major setback for Chelsea, who were below their best and now sit eight points behind leaders Manchester City having only won one of their last four Premier League games
It appeared they had weathered the storm after N'Golo Kante's introduction from the bench midway through the second half helped to tilt the momentum in their favour following a lengthy period of Brighton dominance during which they created a series of chances
But Thomas Tuchel's side, who also lost Reece James and Andreas Christensen to hamstring and back injuries respectively, missed several opportunities to extend their lead in the closing stages before Welbeck's towering header prompted wild Brighton celebrations, handing a major boost to Manchester City and placing added emphasis on Chelsea's clash with Liverpool, live on Sky Sports on Sunday
Chelsea were boosted by Lukaku's return to the starting line-up for the first time in the Premier League since October but, with Marcos Alonso benched and Ben Chilwell out for the season, there was also the more unfamiliar sight of James lining up at left wing-back, with Christian Pulisic filling in on the right
The 22-year-old endured some uncomfortable moments up against his former Chelsea team-mate Tariq Lamptey, who had an early penalty appeal turned down, then cut inside James and fired a left-footed shot a few yards wide
Those moments served as early warnings for Chelsea, but the first big opportunity fell their way when Brighton goalkeeper Robert Sanchez flapped at a corner and Cesar Azpilicueta steered the loose ball onto the post via a deflection
Antonio Rudiger headed straight at Sanchez moments later and Cucurella dragged a shot wide at the other end, but the game's next major incident was James's withdrawal, the wing-back immediately signalling to the bench and needing to be helped off the pitch following a challenge by Lamptey
It was a considerable blow for Chelsea, especially given Chilwell's long-term absence, but their frustration made way for elation moments later when Lukaku outmuscled Neal Maupay and headed Mason Mount's corner beyond Sanchez to put them in front
Maupay required treatment having been caught in the face as he jostled with the Chelsea striker and could be seen protesting to the fourth official as Brighton finally got the game back under way, but by that point, the VAR check had ruled in Chelsea's favour
Brighton, angry that the goal had been allowed to stand, responded strongly and soon began to dominate, unleashing a flurry of shots on the Chelsea goal which included Adam Lallana forcing a fine save from Edouard Mendy and Lamptey looping an effort just over
The visitors were angered again when Antonio Rudiger flew into a tackle on Lamptey, winning the ball but with both feet off the ground
 He was shown a yellow card but the visiting players felt it should have been red
Brighton, though, picked up where they left off after the break, with Alexis Mac Allister, Jakub Moder and the excellent Yves Bissouma all going close before they created their best chance, which saw Maupay's goalbound effort heroically blocked by Rudiger with Mendy out of position
Chelsea continued to look rattled but Kante's introduction, three days after he was feared to have suffered an injury setback in the 3-1 win over Aston Villa, helped them contain the hosts
For a period, the momentum was back with Chelsea
 Rudiger's header across goal was hacked away by Joel Veltman before it could reach the unmarked Lukaku and a last-ditch tackle from Cucurella then denied Mount a one-on-one opportunity
Lukaku then had an even better chance when Kovacic found him in the Brighton box but he opted to cut the ball onto his left foot instead of shooting with his right and Veltman, excellent in the visitors' back three, managed to make another important block
Chelsea had a penalty appeal turned down after Christian Pulisic went to ground on the left-hand side of the box, but Brighton continued to threaten, and their persistence paid off when Cucurella's teasing cross was brilliantly directed into the net by Welbeck and Mendy was finally beaten
The draw sends Chelsea above Liverpool into second place, but the gap to Manchester City looks ominously large for a side increasingly depleted by injuries and Covid-enforced absences
Chelsea were three points clear of Liverpool and four points ahead of Manchester City after 12 Premier League games at the end of November
They now trail leaders City by eight points and are just one ahead of Liverpool with a game in hand
The west Londoners have gone from 15/8 shots with Sky Bet for the title all the way out to 16/1
 And there won't be many takers at that price considering Manchester City's form, and Chelsea's for that matter
 Despite only losing their lead in stoppage time vs Brighton, they were second best for large parts, who pressed efficiently, passed intelligently and looked more confident than their supposed title challenging rivals
Such is the relentless pace at the top of the Premier League, you simply can't afford to go through a spell of winning just four out of 10 games like Chelsea have
 In the blink of an eye, the title has slipped out of their grasp
Sustaining attacks and creating quality chances is becoming a real problem for Thomas Tuchel, who cut a frustrated figure in his media duties after dropping yet more points
 Their lack of sustained, quality attacks can be showcased through an expected goals figure of just 0
67 in the 1-1 draw
 Romelu Lukaku's goal came from a set-piece, as did most of Chelsea's chances
 Remember this is a team that against Arsenal on the second week of the season created 18 chances from open play in one fixture
 Such is their current malaise, they have created a total of 18 chances from open play in their last three fixtures combined against Brighton, Aston Villa and Wolves
It was the same story in the 3-2 win over Leeds where two Jorginho penalties got them out of jail and papered over the cracks of their lack of cutting edge in the final third
 This is now more than just a blip for Tuchel and Chelsea
 They have questions to answer
Chelsea boss : "We knew before that this was going to be a tough match against a strong side
"They come well prepared
 It's always like this
 I have not seen one team play a nice match against them, so it was clear we would struggle
"We simply have way too many players of whom we don't know what we can demand
 They come from long injuries, they come from Covid
 I simply don't know what they are capable of doing
"We started very, very well, until the injury for Reece James, which was a huge blow
 Then we lose Andreas Christensen, who was until then again one of the top players on the pitch
 At some point, it's too much
"Brighton's: "I thought it was a fantastic performance from the players
 It was full of courage and full of quality against a top side
"To come here and be ourselves is a big challenge and I thought we were and that is a credit to the players
 They were fantastic tonight
"We performed well against Liverpool twice away, we have won and drawn there and that is not easy to do
 But tonight was up there that is for sure
"We have celebrated a point but I think it is more the performance and the courage that was shown as a group
 I hope it is something we can take forward
"The Frenchman showed why he is admired by some of the Premier League's top sides with a commanding performance
Bissouma dominated the midfield for long periods, making seven tackles - more than twice as many as any of his Brighton team-mates - and also a number of crucial interceptions and clearances
He shone offensively too, twice testing Edouard Mendy and creating a further two scoring chances for team-mates
 It was a complete performance and one which proved invaluable in helping Brighton claim a deserved point
Chelsea host title rivals Liverpool live on Sky Sports Premier League from 4
15pm on Sunday, January 2; kick-off 4
30pm
 Brighton, meanwhile, travel to Everton on the same day, with kick-off at 2pm
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