Jay Z and West's The Throne collaboration won them Best Group and Video of the Year honours, while Knowles picked up Best Female R&B Artist and Video Director of the Year, opposite her sister Solange's boyfriend Alan Ferguson, reported Los Angeles Times online.
Brown claimed the night's Best Male R&B Artist award and was also voted the fans' favourite artist overall.
It was also a big night for Whitney Houston fans, the late star was the subject of a lengthy and emotionally-charged tribute, which featured a heartfelt speech by Mariah Carey and performances from Monica, Brandy, Chaka Khan and the tragic singer's mother Cissy.
The ceremony also featured a host of stunning performances from the likes of Nicki Minaj, Usher, Tyga, Brown, West and D'Angelo, who made his first televised performance in 12 years at the Bet Awards.
