The groups played across various locations in the Welsh capital, with wristband-wearing fans hopping from venue to venue to catch the acts at the bash, which was curated by BBC Radio 1 DJ Huw Stephens.
The Chapman Family were one of the first bands to play, taking the stage at Tommy’s Bar at 8:20pm (GMT).
Watch video footage of the show by clicking below.
The foursome played a frenetic set that saw them break their equipment, with frontman Kingsley Chapman hurling his guitar violently on the stage floor near the death of the set, destroying it.
Over at the Barfly Max Tundra stood in for Ox.Eagle.Lion.Man, who had to cancel due to personal commitments.
At The Gate Cardiff stalwart John Mouse played before former Boo Radleys man Martin Carr‘s solo set. Stephen Fretwell – who recently played bass for The Last Shadow Puppets – played a solo show to headline.
Hotly-tipped electro-pop trio Chew Lips played an energetic show at the Buffalo Bar, with singer Tigs leaping into the crowd to sing during the end of the set.
Norway’s Casiokids played a similarly-frenetic show at the Kaz Bar, where they attracted a huge crowd before James Yuill‘s headline show.
At the end of the night DJs from the Moshi Moshi record label played hits into the early hours at the Clwb Ifor Bach venue to close the first night of Swn, with fans and bands partying together in the upstairs room at the venue.
See the NME Swn festival blog for more.