Leeds went into the match at the Brentford Community Stadium needing to better Burnley’s result at home to Newcastle, and managed to secure victory over nine-man Brentford as the Clarets slipped to a 2-1 defeat.
Raphinha’s spot-kick gave Leeds the lead in the second half, and Jack Harrison’s injury-time winner ensured Leeds beat the drop after Sergi Canos had equalised for the Bees.
Marsch believes securing promotion has started the process at Leeds, but admitted there is a lot more to do.
It's almost been a band aid project than it has been a project about style of play and identity and developing an academy
“It’s almost been a band aid project than it has been a project about style of play and identity and developing an academy,” the American manager said.
“I mean, there’s so much to do. I think we’ve really started the process in a good way and we’ve invested in each other and in what we have as a from a resource and player and person, and people perspective.
“But I think we’re just scratching the surface of the potential of what we want to become, so there’s a lot do.
“I mean, it’s almost everything, but I am so thankful to work with the people that I work with every day, and I knew that regardless of the outcome of today that we have a big future because of the people that are involved.”
Thomas Frank believes Brentford’s 13th-place finish in their first Premier League season has shown their worth.
“I think we showed that we could be an asset to the Premier League and that’s what I’m most proud of,” the Bees boss said after their final match of the season.
“I’m very proud of the overall performance and the way we presented ourselves as players and as a team.”
Frank added: “I think that we have done (a) remarkable (job).”
“I am very, very respectful about this league, (and) I don’t believe in second season syndrome or that narrative.”