The 27-year-old soul singer-songwriter beat off stiff competition from Jessie J, Jessie Ware, Lianne La Havas and Rita Ora to win Best Female Act and also picked up the award for Best R&B/Soul Act.
Naughty Boy, whose real name is Shahid Khan, won Best Song for his hit 'La, La, La' featuring Sam Smith, as well as Best Video for the same track.
'Boom Blast' hitmaker Wiley, who received the most nominations with four categories, took home one award for Best Male Act.
Other big winners included electronic act Rudimental, who won Best Album for 'Home,' and Tine Tempah who was named Best UK Hip Hop/Grime Act.
Kendrick Lamar was named Best International Act ahead of his fellow nominees Justin Timberlake, Ciara, Iggy Azalea, J.Cole, Jason Derulo, Jay Z, Kanye West, Miguel and 'Blurred Lines' singer Robin Thicke.
The 18th annual awards ceremony took place at the SSE Hydro in Glasgow, Scotland, and featured performances from acts including Tinie Tempah, Rudimental and Iggy Azealea.
Full List of 2013 MOBO Winners:
Best Newcomer in association with HTC:
Krept and Konan
Best Male Act:
Best Female Act In association with Tresor Paris:
Best Video in association with SBTV:
Naughty Boy feat. Sam Smith - 'La La La'
Best UK Hip Hop/Grime:
Rudimental - 'Home'
Best R&B/Soul Act:
Best Song in Association with PRSforMusic:
Naughty Boy - 'La La La'
Best International Act:
Best African Act:
Best Jazz Act:
Sons Of Kemet
Best Gospel Act:
Best Reggae Act:
Stephen Lawrence Trust