Grime’s grip on the music industry was reaffirmed at this year’s Ivor Novello awards as Skepta won two of the biggest accolades.

The star was named songwriter of the year and also won for best contemporary song.

As well as a sign of his recent success, it marked a departure for the Ivor Novellos. The ceremony is intended to acknowledge talent in songwriting but has often been seen as overly dominated by white artists, with Adele, James Bay and Ed Sheeran the big winners in recent years.

George Clinton, a major architect of funk, with wife Carlon Thompson-Clinton Photograph: Dave J Hogan/Getty

Skepta, real name Joseph Junior Adenuga, and his crew of artists operating under the banner of Boy Better Know have championed grime in the mainstream and brought it to an international audience over the past year. He was visibly shocked by his two awards at the ceremony in London on Thursday, and was presented with the songwriter of the year trophy by his sister, radio host Julie Adenuga.

“I could talk about the time he bleached his hair blond, that we dressed up as Mortal Kombat characters, but I’m not going to do that,” she said. “I’m going to tell the story of how, from day one, our family has been about creation – sometimes because we couldn’t get some things, mostly because of the luck we made. So to stand here in 2017, and present my brother with this award, I’m just so excited to see people celebrating him, appreciating him, applauding him and rewarding him.”

Before handing him the microphone, she joked that while he had been named songwriter of the year, one of his lyrics was “ring, ring pussy, it’s your mama on the phone”.

Skepta said he had recently “really fallen in love with songwriting. It’s helped me out through my life and I understand that in any time in my life I understand that the reason I’m so easy with bad times now is that I’m like ‘Oh, another song’s coming’. Songwriting has really allowed me to enjoy life and look at it from an objective place.”

He won best contemporary song for Man, which sampled a Queens of the Stone Age track.

Skepta’s award-winning song Man

“So many people are writing music around the world for different things and different reasons,” Skepta told the audience. “Songs like One Love by Bob Marley – they stand the test of time, it doesn’t matter, so anytime I write music I try to write in tune with an emotion and I hope there are more times like that for everyone.”

The Ivor Novellos triumph follows Skepta’s Mercury prize win in September last year. His fourth album, Konnichiwa, was also nominated for a Brit award.

Jarvis Cocker on his way to the ceremony. Photograph: Rex/Shutterstock

The Ivor Novello for outstanding song collection went to Pulp. Collecting the award, outspoken frontman Jarvis Cocker touched on the “dirty word” that is Brexit.

He said: “There was referendum almost a year ago – we all know the results, 52/48. I want you to transfer that into chart terms; that means the equivalent of your single going in at No 19 in the top 40. That’s not a hit, that’s not the will of the people.”

Award-winner Laura Mvula. Photograph: Dave J Hogan/Getty

The award for best song musically and lyrically went to Michael Kiwanuka for Black Man in a White World. Best album went to The Dreaming Room by Laura Mvula who, despite being nominated for the Brits and the Mercury prize, was dropped by her label Sony this year, a moment she has described as “devastating”.

Michael Kiwanuka, Black Man in a White World

The award for most performed work went to Coldplay – the band’s third Ivor Novello – for the song Hymn for the Weekend. Florence Welch from Florence + The Machine received the international achievement award.

Bill Withers, the 78-year-old US soul artist known for tracks such as Ain’t No Sunshine and Grandma’s Hands, was also honoured with a special international award. “I’m proud and humbled to be included,” he said.

Nitin Sawhney with the lifetime achievement award. Photograph: Ian West/PA

Nitin Sawhney, the British-Indian musician and producer who pioneered world music fusion in the 1990s, picked up the lifetime achievement award.

Anne Dudley, best known as a core member of Art of Noise and who has had a two-decade career composing film scores including The Crying Game, The Full Monty and Les Misérables, was awarded the outstanding contribution to British music prize.