The Brazilians are clear favourites heading into the last eight first leg at Loftus Versfeld on Friday.
Sundowns though ended in second place in their qualifying group, while Stade Malien exceeded expectations by finishing above ES Tunis, Petro de Luanda and Simba to secure their knockout spot.
Despite his side's poor domestic form of late that sees Stade Malien occupy eighth place on the current Malian Premier Division standings, Njoya believes that his team can overcome the 2016 CAF Champions League winners.
The Cameroonian coach said on KickOff: "In football, there are a lot of surprises. Those so-called small teams can surprise big teams.
"Even for us, if we are playing against a team that some may call a small team, we are always going for the win.
"But if they call us a small team, we will also go for the win against a big team."
Njoya added: "The Champions League is where we want to be. It is where the biggest teams in Africa compete.
“So we are here not just to visit, we are here to stay. We want to be one of the best in Africa.”
Mamelodi Sundowns coach Miguel Cardoso is expecting a competitive and physical encounter against Stade Malien in the first leg of their CAF Champions League quarter-final.
Mamelodi Sundowns will be facing opposition from Mali for the first time when they host Stade Malien in the CAF Champions League quarter-final first leg on Friday.
Orbit College coach Pogiso Makhoye was disappointed with his side's defending as they went down 2-0 to Mamelodi Sundowns at Olympia Park on Tuesday night.
Mamelodi Sundowns striker Iqraam Rayners admits it's a relief to be back in action and scoring goals for Mamelodi Sundowns after a lengthily spell on the sidelines.
