Pia Sundhage's side currently sit in second place with a three-point lead over Tuesday's opponents and third-placed China PR Women, meaning a point on Tuesday would confirm a top-two finish, while Zambia Women will likely have to battle to progress as one of the best third-placed sides.
Match preview
Having come into the tournament as one of the favourites to earn a medal, Brazil Women started their group campaign in style, thrashing China PR Women 5-0 in Rifu.
Goals from Marta and Debinha gave them a 2-0 lead in the first half before Marta netted her second and Andressa and Beatriz scored late on to seal an eye-catching victory.
They would then face a tougher test in the following game last time out, as they took on a Netherlands Women side who boasted a superior goal difference thanks to a 10-3 win in the opening game.
Despite going down on two separate occasions, Brazil would fight back to go 3-2 up after 70 minutes thanks to goals from Marta and Ludmila, only for Dominique Janssen to draw Netherlands Women back level with 10 minutes to go.
While they will have been disappointed not to hold on for another win, Sundhage's side all but confirmed their progression with that point, now sitting three points clear of both Zambia Women and China PR Women with a far stronger goal difference than those two sides.
As a result, Brazil Women simply need to avoid a defeat on Tuesday to confirm a finish in the top two, although they would stand a strong chance of progressing as one of the best third-placed sides even if they were somehow overtaken on the final day.
Their opponents have the much tougher task of picking up a positive result on Tuesday in their bid to qualify for the knockout stage against the odds.
In their first ever appearance at the Olympic Games Women's Football competition, the Zambian side took on a heavily-fancied Netherlands Women team, and they would not be given an easy start to life on the world stage.
Their opponents took a three-goal lead inside the first 15 minutes thanks to a Vivianne Miedema brace and a Lieke Martens goal, but Barbra Banda would pull a goal back for Zambia Women.
That would quickly become inconsequential as Miedema netted two more and Martens again found the net alongside Shanice van de Sanden, Jill Roord, Lineth Beerensteyn and Victoria Pelova to see Netherlands Women take a 10-1 lead before Banda netted two late goals to complete her hat-trick in a 10-3 defeat.
Bruce Mwape's team would then take on a China PR Women side fresh off a 5-0 defeat to Brazil Women, with the result potentially crucial in deciding who earned third spot.
That game did not start well for the Zambian national side as Wang Shuang gave China the lead after just six minutes, but Racheal Kundananji would level the game in the 15th minute before Shuang completed her hat-trick to put their opponents 3-1 up in the first half.
Banda would then hit her second consecutive hat-trick to turn the game on its head, putting Zambia 4-3 up heading into the final five minutes before China Women earned a penalty that Shuang converted to see the sides split the points following a dramatic 4-4 draw.
While their concerning goal difference tally means Zambia Women should fall short of the top two, they still stand a chance of reaching the quarter-finals if they manage to earn a victory on Tuesday, as two of the best third-placed sides will qualify from the group stage.
Brazil Women Olympic Games Women's Football form:
Brazil Women form (all competitions):
Zambia Women Olympic Games Women's Football form:
Zambia Women form (all competitions):
Team News
Brazil stuck with an unchanged side for the second group game, and Sundhage is expected to again deploy the same starting XI on Tuesday after two impressive team performances.
Marta should again play a key role, having hit three goals in their first two goals of the group stage.
She will be supported in attack by Debinha, who netted the opening goal in their draw with Netherlands Women.
At the age of 43, midfielder Formiga continues to be a key player for Sundhage's side, and she should again be deployed from the start although is regularly substituted off early in the second half.
Despite Zambia's struggles at the Olympic Games Women's tournaments, Barbra Banda made history by scoring their first goal in Olympic history, and she has shown fine form with hat-tricks in both of their games so far.
Mary Wilombe was forced off in the first half last time out, and she could miss out through injury on Tuesday.
However, Martha Tembo did return from suspension to replace Wilombe off the bench in that game, and she should be lined up to feature from the start in the crucial upcoming game.
Brazil Women possible starting lineup:
Barbara; Tamires, Rafaelle, Erika, Benites; Debinha, Andressinha, Formiga, Duda; Marta, Beatriz
Zambia Women possible starting lineup:
Nali; Kundananji, Musase, Mweemba, Siamfuko; Lungu, Tembo; Chitundu, Chanda, Ochumba; Banda
We say: Brazil Women 4-2 Zambia Women
Zambia Women have shown that they have the attacking ability to pose a threat to any side in the competition, and they should form a challenge for Brazil, but we ultimately see the South American side coming out on top.
Brazil Women look to be a strong unit and will hope to finish on the podium, and we do not see Mwape's side being strong enough at the back to stop them securing another victory.