The Lily Hill men went into the contest on the back of their 119-0 hammering of High Wycombe and were hot favourites to extend their unbeaten start to the season.
But it was far from another one-sided affair as Marlow, who had lost just once prior to the weekend in South West One East, pushed Bracknell all the way to the final whistle.
"I think last week lulled us into a bit of a false sense of security," Bracknell head coach Greenslade-Jones told the News.
"First half we thought we could score on every occasion but actually they are a very good team and it took us coming together and having a chat at half time, setting some realistic goals, and then putting those into practice with a good second-half performance."
* SEE THIS WEEK'S NEWS FOR FULL INTERVIEW AND MORE BRACKNELL RFC NEWS.