It means a repeat of this season’s Carabao Cup Final, which Jurgen Klopp’s side won after 22 penalties eventually separated the two teams.
So, this 2-0 win against Palace provides Tuchel with the chance to enact swift revenge and, who knows, deny quadruple-chasing Liverpool a clean sweep.
Klopp’s side will certainly have to do it the hard way if they are to complete the unprecedented feat of lifting all three domestic trophies and the Champions League as well.
Victory, meanwhile, keeps Chelsea’s season alive, as well ensuring Tuchel remains a fascinating sub-plot to the Klopp-Pep Guardiola narrative.
While Liverpool and Manchester City are on course to determine the two biggest prizes of the Premier League and Champions League, Klopp will have had to overcome Tuchel in both domestic cups if he is to achieve his ambitions this term.
That, in itself, should serve as a reminder of how close Chelsea are to the undoubted leading pair in English and, possibly, European football.
Tuchel is convinced his team would still be in the conversation for the title if not for injuries and Covid having such an impact midway through the campaign.
That is up to him to prove next season, but his performance in just about every other competition adds weight to his claim.
The European Super Cup and Club World Cup have already been won this season.
The Carabao Cup was lost on penalties, while their defence of their Champions League crown was ended in heart-breaking circumstances against Real Madrid on Tuesday night.
Now Tuchel has extended his record of reaching every domestic cup final possible since taking over at Stamford Bridge last year, with this latest win.
It is the third year in succession Chelsea have reached the FA Cup Final – now they need to complete the job after going on to lose in each of the last two years.
This was not pretty – and the score flattered Chelsea.
It was also cruel on Palace, who had presented numerous problems to their opponents – requiring Edouard Mendy to produce a wonderful save to deny Cheikhou Kouyate with the scores level.
For long periods they lacked energy and inspiration – and the question was always going to be how they recovered from the exertions and emotions of their midweek Champions League elimination.
A Wembley semi-final gave them no opportunity to feel sorry for themselves – especially against a Palace side whose supporters treated the occasion like a final.
Blue and red flags filled the Palace end, with flares let off before the first whistle adding to the atmosphere.
Could Chelsea’s fans, let alone the players, match that anticipation?
Palace were ready to seize on any error with Wilfried Zaha, Jean-Philippe Mateta and Eberechi Eze all threatening on the break.
Only the alertness of Andreas Christensen kept them at bay in the first half, while Kouyate’s volley nine minutes before the break was brilliantly pushed away by Mendy.
Chelsea offered little in response, with a dive from Kai Havertz on the edge of the box earning the German and yellow card and denying himself a clear run on goal.
Kouyate had the first real chance of the second half as well when he rose higher than anyone else to meet a corner – but headed wide with Mendy rooted to the spot.
That miss grew in importance when Chelsea went ahead in the 65th-minute, with a touch of fortune proving decisive.
When Tyrick Mitchell lost the ball in his own half, Chelsea burst forward.
Havertz twisted in the box before driving a hopeful ball across the goal.
The excellent Marc Guehi’s trailing leg inadvertently diverted it into the path of substitute Ruben Loftus-Cheek, who lashed a shot into the top corner that took a slight deflection off Joachim Anderson.
Whether Jack Butland would have been able to stop it without that touch is debatable – but it was a case of the breaks going for Chelsea and against Palace.
The game was over in the 76th-minute when Mason Mount added a second.
Havertz lofted ball was controlled by Timo Werner on his chest. He laid off to Mount, who gave it back.
Werner then showed composure to wait for his chance to feed Mount in the box and the midfielder slid a shot past Butland.
Late on Chelsea could have extended their lead when Romelu Lukaku came off the bench and hit the post with an open goal in front of him.
By then the day’s job was done. Now they need to complete it against Liverpool.