Among those congratulating her: ex Chris Brown, who greeted the star – with a kiss.
The former couple were photographed sharing a smooch as the singer returned to her seat after accepting honors for "We Found Love," which features the chorus about experiencing romance "in a hopeless place."
Their friendly display at L.A.'s Staples Center comes after Rihanna's recent revelation that she still has feelings for Brown, 23, whose relationship with the singer, 24, was marked by a domestic violence drama that unfolded in headlines more than three years ago.
"I truly love him," she told Oprah last month during an emotional interview, in which she confirmed that they had reconnected in St. Tropez earlier in the year. "And the main thing for me is that he is at peace. I'm not at peace if he is unhappy or he is still lonely. I care."
Brown also earned honors at the ceremony in the categories of best male video and best choreography.