(Football news) Conor Gallagher gave Chelsea the early lead before Palmer scored from the penalty spot, giving Chelsea a 2-0 lead after just 19 minutes.
But Manchester United appeared on track for a massive three points in the English capital as Alejandro Garnacho scored either side of a header from Bruno Fernandes to turn the tide of the game.
Palmer, however, had other ideas. Less than a minute later, the Blues won it under unusual circumstances after Palmer scored his second penalty of the game in the tenth minute of extra time at the end of the ninety-minute mark.
Manchester United remain sixth in the Premier League table, nine points behind fifth-placed Tottenham Hotspur, while Chelsea have risen into 10th, now just five points off the Red Devils with a game in hand.
Manchester United’s minority shareholder Sir Jim Ratcliffe was present at Stamford Bridge, and he witnessed the worst of the 20-time English champions on Thursday night.
Malo Gusto was fit to start for Chelsea despite fears that he had suffered a hamstring issue against Burnley at the weekend, but there was no Ben Chilwell for the Blues.
Manchester United’s major team news involved Marcus Rashford, with the England international dropping down to the bench, which allowed Antony to come into the starting side at Stamford Bridge.
The visitors had a half-chance inside the first minute when a break down the right led to Antony having a strike towards goal after combining with Aaron Wan-Bissaka, but his attempt was blocked.
Chelsea made the breakthrough in the fourth minute of the contest, with Gallagher striking into the back of the net from inside the box after Gusto’s cross had been deflected into his path; Andre Onana might have done better between the Manchester United sticks, with the ball going underneath the goalkeeper.
Antony curled the ball towards the home side’s goal in the eighth minute, but Chelsea stopper Djordje Petrovic was on hand to make the save, before Mykhaylo Mudryk had one deflected just wide of the target down the other end moments later, with neither team looking secure at the back.
Marc Cucurella swept one over the Manchester United crossbar in the 15th minute, before Garnacho tried a spectacular volley down the other end from a Kobbie Mainoo cross, but his effort was nowhere near the target.
Chelsea were then awarded a penalty in the 18th minute when Antony brought Cucurella to the ground inside the box, and Palmer stepped up to send the Blues two goals ahead at Stamford Bridge.
Mudryk found the side-netting at the end of another quick Chelsea break in the 28th minute, before Diogo Dalot had one deflected over the crossbar down the other end, and Mainoo then tested Petrovic from distance with a powerful strike.
Manhester United were back in the match in the 34th minute, though, with a poor pass from Moises Caicedo releasing Garnacho towards the Chelsea goal, and the Argentine expertly picked out the back of the net under pressure from Blues defender Benoit Badiashile.
Onana made a smart save to keep out a strike from Enzo Fernandez in the 38th minute, before the Red Devils incredibly managed to level the scores one minute later, with Fernandes heading an excellent cross from Dalot into the back of the net at the far post.
Gallagher sent one wide of the Man United goal in the 43rd minute, before striking the post shortly after, and the half-time whistle was blown at 2-2 following five additional minutes at the end of the first period.
Man United suffered yet another defensive injury in the first half at Stamford Bridge, with Varane feeling his hip, and the Frenchman did not emerge for the second half, as Jonny Evans replaced him.
Maguire fired one over the Chelsea crossbar early in the second period, before Evans did brilliantly to block a strike from Fernandez down the other end, with neither side able to keep hold of the ball.
Onana was called into action to deny Nicolas Jackson in the 53rd minute, before Fernandes struck one over the crossbar down the other end during an incredible period of the match.
Rasmus Hojlund was next to burst through on the Chelsea goal in the 57th minute, but the forward was denied by a last-ditch challenge from Axel Disasi, who had initially given the ball away; Casemiro then headed the resulting corner over the crossbar from close range.
Onana then kept out Palmer in the 59th minute, before Rashford and Willy Kambwala entered the field for the Red Devils in the 66th minute, with Evans, having picked up another injury, departing alongside Hojlund.
Manchester United took the lead in the 67th minute, with Garnacho heading a brilliant delivery from Antony into the back of the net after the Brazilian was given space down the right, and it proved to be the much-criticised forward’s first assist of the campaign.
Onana did well to keep out a rasping Palmer free kick in the 74th minute before Disasi headed over the Manchester United crossbar from the resulting corner. Alfie Gilchrist had a free header inside the Man United box in the 78th minute, but he headed over, with Chelsea on the front foot at Stamford Bridge.
There were huge boos around the stadium when Mason Mount entered the field for the visitors in the 85th minute, with two-goal Garnacho being replaced after putting in an excellent performance.
In the last minutes of extra time, Noni Madueke tested Onana, and the home team’s substitute subsequently got a penalty after Dalot challenged; Palmer stepped up for the Blues, scoring his second spot kick of the game to tie the score at three.
The former Manchester City youth player then completed his hat-trick in the eleventh minute of added time, setting off joyous celebrations at Stamford Bridge. Palmer then won it for the hosts with a deflected strike.
On Sunday, both teams will play in the league again. Chelsea will travel to Sheffield United, who are in danger of relegation, while Manchester United will host title-chasing Liverpool at Old Trafford.
Also read: Manchester United will play Chelsea in EPL
