The American quickly found out what it is like to be in charge of a Leeds team as the Whites failed to put the finishing touches to some smart approach play and ended the game effectively with 10 men after the last of their three substitutes, Tyler Roberts, was injured shortly after coming on.
He bravely carried on, but was a passenger in the closing stages with United unable to mount much pressure at the end to hit back after falling behind to a second half goal.
The scorer of the home side's only goal should have been no surprise as it was winger Harvey Barnes, who has now scored on all four of his outings for Leicester against Leeds.
Coaches change, but it seems some things do not - and it is not just at the back that the new boss has got to improve things with United as they failed to score despite having 19 attempts on goal.
Marsch reflected on his unfortunate start.
He said: "I've learned - this is maybe the American in me - that sometimes our sport isn't the fairest, but it doesn't matter, you've got to do what you can in this sport to manage.
"In a sport like basketball you score a lot more points and the better team manages to emerge.
"I'm not saying we were the better team, but what I'll say in general is I am very pleased that after four days and where we've changed a lot of tactical topics and we've changed a lot of what we're trying to accomplish on the pitch that there was such clarity and that we were able to execute in every phase of the game, and we were able to put into practice.
"What I find with the group is now that I know how hard they work, I know how committed they are to each other on the pitch, I know how hard they want to make the fans proud.
"What I also learned today is how intelligent they are, how they were able to take a lot of our video sessions and some of the work we've done on the pitch in segments and after four days put in a performance like that at a tough moment for us in the season, at a tough place to play, against a good opponent.
"I'm very positive even though we're disappointed with the result. Certainly, we need to use this as momentum to continue to propel us to get better and better.
“For the most part, the basics were quite good and for me if if we had found the first goal it’s a different type of match.
On what Leeds could improve ahead of back to back home games ahead now in the next week against Aston Villa and Norwich, Marsh explained: "During the match I can see little things where we can be a little bit sharper and clearer with our tactical understanding with and without the ball and our movements.
"For the most part, the basics it was quite good and so we just need to be a little bit sharper in the last third a little, clearer with some of the relationships and maybe luck and maybe then we find ourselves a lead and some points.
“It will be more about creating clarity now with the things that happen in the game, that can be tighter and better understood.
“But at the same time, really, in a tough moment in a big game where there is stress I thought their ability to execute was really good.
“There are so many little things happening on the pitch that can be a little bit cleaner, it will take time to implement it fully.
“These guys run and fight for each other so much, I am just trying to guide them now. If we keep playing like this we can get all the points we need.”
Marsch picked a line-up almost identical to Marcelo Bielsa's in his last game in charge, but changed the formation a little and tactics as he went with more of a 4-2-3-1 formation, giving the beleaguered back four some more protection.
It worked in making the Whites look a lot more solid while they still poured forward and created plenty of opportunities with Dan James and Jack Harrison in particular looking lively.
Just the finish was missing and a little luck as they could have been awarded a penalty at 0-0 when Rodrigo was brought down in the area, but the shout fell on deaf ears. Marsch will quickly find out that it is never straight forward with this club.
James had the first real chance of the game when he racing in behind the Leicester defence from Rodrigo’s pass, but his angled shot was well saved by former Leeds keeper Kasper Schmeichel, who went on to be the home side's man of the match.
Illan Meslier made a decent save at the other end to deny Barnes when he cut inside from his wing.
In a lively opening Robin Koch, still playing in midfield, hit a shot wide and Luke Ayling sent a header over.
Harrison then found space in the area following a good move only to see his angled shot saved by Schmeichel.
On another day Leeds would have been awarded a penalty when Rodrigo and Caglar Soyuncu challenged for the ball in the box and the City defender missed the ball and made contact with his opponent. But nothing was awarded and it was not considered a clear and obvious error by VAR.
Another chance fell the Whites' way when Rodrigo’s cross fell to Junior Firpo, but his shot was blocked.
Raphinha also had a shot blocked, while Wilfred Ndidi's header forced a save from Meslier with Leicester reminding their visitors that they could also be dangerous going forward.
The second half saw less action initially before bursting into life with Harrison having a shot deflected wide and from the resulting corner Rodrigo getting in a near post header that had to be kept out by Schmeichel.
United's best chance of the afternoon followed as Firpo's fine low cross found Raphinha in the middle, but the Brazilian saw his close range shot saved by Schmeichel's legs when it looked easier to score.
Joe Gelhardt came on to replace Rodrigo and within seconds was in the thick of the action as Raphinha found him in the area, but his shot was deflected wide.
It seemed a goal had to come, but it was Leicester who found it as their substitute Kelechi Iheanacho put Barnes into space in the area and the latter's confident finish made it 1-0.
Leeds found it much harder to create chances from this point and it became more comfortable for their hosts to see out the game once Roberts was injured after he had surprisingly been sent on for Harrison despite the presence of Patrick Bamford on the bench.
Saturday, March 5, 2022
Leicester: Schmeichel; Choudhury (Lookman 61), Amartey, Soyuncu, Thomas; Tielemans, Ndidi( Mendy 76), Dewsbury-Hall; Albrighton, Vardy (Iheanacho 61), Barnes.
Leeds: Meslier; Dallas, Ayling, Struijk, Firpo; Koch, Klich (Forshaw 69); Raphinha, Rodrigo (Gelhardt 63), Harrison (Roberts 76); James.
Referee: David Coote