Christian Pulisic spared Jorginho's blushes as his 90th-minute winner earned Chelsea a 1-0 victory over 10-man West Ham - to end the Blues' awful record at Stamford Bridge.
Chelsea thought they were heading towards a goalless draw when Italian midfielder Jorginho tucked an awful penalty straight into Lukasz Fabianski's clutches with five minutes remaining.
But with West Ham stretched after going down to 10 men after Craig Dawson's red card for hauling down substitute Romelu Lukaku for the penalty, Marcos Alonso crosses for Pulisic who slotted home from inside the area as the clock ticked into injury time.
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The result solidified Chelsea's place in the top four and ended a run of three home defeats in a row. The Hammers, who made six changes before kick-off including placing Declan Rice, Michail Antonio and Jarrod Bowen on the bench, can now look towards Thursday's Europa League semi-final with Eintracht Frankfurt after missing the chance to leapfrog Manchester United in fifth spot.
The Blues made three changes from the side that lost to Arsenal 4-2 and they were forced into a fourth just before kick-off, with Andreas Christensen picking up an injury in the warm-up and being replaced by Trevoh Chalobah for his first Blues appearance in nearly six weeks.
It was that defensive switch that led to some nervousness for the Blues in the first half, as they got used to the new centre-back partnerships. Said Benrahma picked the pocket of Cesar Azpilicueta, unusually playing on the left of a back three, before firing a shot straight at Edouard Mendy from a tight angle.
Minutes later, the Hammers winger caught Chalobah high in possession on the other side, but Thiago Silva's last-ditch challenge denied the Algerian a second shot on goal in a much better position.
Chelsea's first-half chances were few and far between, with all of their efforts coming from distance. N'Golo Kante curled an effort with his weaker left foot wide of Fabianski's post, while Mason Mount's effort from further out wasn't much closer.
Meanwhile, West Ham's confidence at the other end of the pitch was growing. The Hammers spurned the best chance of the half when Andriy Yarmolenko's run to get onto Pablo Fornals's pass deceived all of Chelsea's back three, but the Ukrainian could only hook an effort wide of goal.
Chelsea's urgency improved after half-time and so did the Stamford Bridge noise, with the club still around 10,000 fans light in attendance due to the sanctions placed on Roman Abramovich. Timo Werner's goalbound snapshot was excellently blocked by Craig Dawson, who blocked two more efforts from the German in the space of a couple of minutes.
But West Ham provided a reminder of the threat they posed on the bench. Ben Johnson's excellent pass down the right fed Yarmolenko, who cut inside to set up Soucek on the edge of the box, but Silva was there to put in another important intervention.
The end-to-end encounter improved, with Kante going on a mazy run towards the edge of the box and his left-footed effort took a wicked deflection that nearly deceived Fabianski, who held the ball well.
Chalobah then let fly from 35 yards which Fabianski was equal to - and with Chelsea starting to warm up, West Ham brought on Rice to help out the struggling Hammers midfield.
Yet that switch didn't appear to work Chelsea continued to probe the Hammers backline. Mason Mount's goalbound shot was blocked by Dawson once again, while Werner could not hit the target from the side netting.
Moments later, Mount got down the left and fed Marcos Alonso in the box with a cutback, but the Spaniard mishit his shot and it bounced wide. The Chelsea full-back then had a header at the back post which bounced on the top of Fabianski's net. Alonso then crossed for Werner in the box, but the German's acrobatic effort was straight at the West Ham shot stopper.
With West Ham continuing to put bodies on the line, Tuchel reshuffled his entire striker pack as Hakim Ziyech, Lukaku and Pulisic came on for Werner, Kai Havertz and Ruben Loftus-Cheek.
And it was the Belgian striker who made a near-immediate impact as he latched onto Silva's flick-on to go through on goal, but Dawson tugged him back for a clear spot-kick.
Referee Michael Oliver initially gave Dawson a yellow but VAR instructed him to upgrade it to a sending off. Yet the Chelsea cheers soon turned to despair.
Jorginho did his traditional hot, skip and jump but tucked the effort straight into Fabianski's clutches, in what was an awful penalty.
Yet the Italian became the most relieved man in west London as the Hammers failed to stop Alonso's cross from the left and Pulisic was there to finish first time to send Stamford Bridge into a frenzy.
It could have been more for the Blues as Mount's long-range strike was inches from Fabianski's far post, but despite some late pressure from Chelsea, they held on for a morale-boosting three points.
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Tuchel: Chelsea felt a bit stuck | Moyes rues Dawson red
Tuchel was a relieved man after the match given the spectacular and topsy-turvy moments in the last few minutes of the game. But the German manager accepted that the Blues' display before that was a bit lethargic and that their recent home form impacted them in this match.
"It seemed a bit stuck," the German told Sky Sports. "But we knew it. It can feel like this against West Ham who defend with a lot of bodies and discipline. We have to wait for the moments. We had some accelerations with Mason from midfield but nobody was joining.
"It felt stuck. We controlled the game but could not find spaces. It was also not the moment to take every risk after our recent results. We wanted to control their counter-attacks. The red card maybe opened more space to allow the late answer."
Tuchel also leapt to the defence of Jorginho - with the Chelsea manager admitting the Italian is "very upset" with himself after his late miss.
"Jorgi had a perfect record with us so there is normally a belief and we had the belief that we had to score the goal we needed," he added. "He has a certain style of shooting when he scores.
"When he scores, he looks unbelievably cool and calm. When he misses, it looks like he could have done better but he's very upset with himself."
Meanwhile, West Ham manager David Moyes rued his side's composure in the last few minutes of the game and believed defender Dawson should have done better to prevent him getting sent off.
"It [the result] a little bit undeserved but we have ourselves to blame. We didn't defend well in the last four or five minutes.
"Dawson played ever so well, I think he should have got the ball. He made the referee make a decision by using it with his left foot.
"There's no criticism of Dawson but if he tried to get the ball quickly then he could have prevented it. Small things in football make the difference, but he [Jorginho] could have still scored and it was 11 v 11."
Tuchel's brave triple sub pays off
Analysis from Sky Sports' Sam Blitz at Stamford Bridge:
Christian Pulisic got the plaudits for his late goal but Thomas Tuchel should really take the full credit for making a brave call with 15 minutes remaining.
The Blues were knocking on the door with the likes of Timo Werner, N'Golo Kante and Mason Mount all going close in a brief five-minute period. Tuchel then took off his entire attack, including the promising Werner, with Romelu Lukaku, Hakim Ziyech and matchwinner Pulisic all coming on.
Replacing a front three that was just starting to click into gear was a bold move but come full-time, the German's tweaks were justified. Lukaku became the focal point in the Blues attack, winning the penalty which resulted in Craig Dawson getting sent off.
That meant more space for Chelsea to manoeuvre in the final few minutes after Jorginho's penalty. Alonso took advantage, crossing for Pulisic to finish.
"I am happy for [Lukaku]," Tuchel told Sky Sports after the game. "I told him he had a good impact. Romelu was involved with the penalty. Hakim was dangerous and Puli got the goal. He lacked confidence in recent matches."
From concerns over a misfiring front line, Chelsea suddenly seem to have plenty of attacking options with the FA Cup final looming. Places are now up for grabs - and the Blues players played like they had a lot on the line in the second half.
For West Ham, the focus was clearly on Thursday night's Europa League semi-final with Eintracht Frankfurt. That was pretty clear before kick-off.
Going into this game, West Ham had made the fewest (47) alterations to their starting eleven in the Premier League this season and averaged just 1.4 changes per matchday. David Moyes made six ahead of this clash.
"Today was the first time we put ourselves in a position where we changed the first team," said Moyes. "I did because it's such a big event on Thursday night.
"We were playing against Chelsea and maybe Chelsea aren't at their sparkling best but we did a lot of good things defensively with a jumbled up back five. I think a lot of players in the squad who haven't played did really good job.
I thought Ben [Johnson] done well in the game today, it gives us some food for thought [with regards to playing him as a centre-back]."
Man of the match - Marcos Alonso
Sky Sports pundit Gary Neville at Stamford Bridge:
"It was a poor performance from Chelsea. I think they have been well off it, but Alonso got the assist for the winning goal, and I think he's kept going down the left.
"He put a couple of good crosses in and his game has been pretty consistent."
What's next?
Chelsea have a packed agenda between now and the end of term, owning to their progression in the FA Cup; they next face Manchester United, live on Sky Sports; kick-off 7:45pm; before a trip to Everton later the same week, live on Super Sunday; kick-off 2pm.
West Ham face a similar amount of remaining fixtures, thanks to their successful Europa League campaign; they host Eintracht Frankfurt before entertaining Arsenal at London Stadium, live on Sky Sports; kick-off 4:30pm.
Chelsea's remaining fixtures
April 28 - Man Utd (a), live on Sky Sports
May 1 - Everton (a), live on Sky Sports
May 7 - Wolves (h)
May 11 - Leeds (a), live on Sky Sports
May 14 - Liverpool (n), FA Cup final
May 19 - Leicester City (h)
May 22 - Watford (h)
West Ham remaining fixtures
April 28 - Eintracht Frankfurt (h), Europa League semi-final first leg
May 1 - Arsenal (h), live on Sky Sports
May 5 - Eintracht Frankfurt (a), Europa League semi-final second leg
May 8 - Norwich (a)
May 15 - Man City (h), live on Sky Sports
May 22 - Brighton (a)