Brookes, brand ambassador and internal communications executive at the Nitro Group, was named Most Talented Adlander out of eight contestants and three finalists at the first 44 Club Adland's Got Talent contest.
Her spoken word performance included the line "I am me, what you get is what you see, that is if you're seeing me and not who you expect me to be ..."
It was described as "powerful, personal and moving" by the judges who also commented that "the audience practically stopped breathing and really listened".
The other two finalists were Steak Digital's Melanie Clark with her rendition of 'Son of a Preacher Man', and the IPA's Will Hanmer Lloyd performing stand-up comedy.
M&C Saatchi was also awarded the Agency Cup for having the most talented number of agency contestants.
The event was chaired by TBWA chief executive Matt Shepherd-Smith with industry judges:
- Moray MacLennan, IPA president and chairman of M&C Saatchi Europe
- Kate Stanners, creative partner at Saatchi & Saatchi
- Sarah Gold, managing partner of CHI & Partners
- James Murphy, founder of Adam & Eve
Shepherd-Smith said: "I was gobsmacked by two things, firstly the quality of the contestants -- the hidden talent in our industry is incredible, and secondly how much the judges really got into it.
"I think they quite literally thought they were on the telly!"
Brookes said: "I've never entered a competition for my 'spoken word' before despite having performed around London for over two years so I'm really chuffed to have won and found it a really entertaining evening."