"Warrior" was written by Jonas Saeed, Niclas Kings, Luciana Caporaso, Nick Clow and Sabi, Jonas Saeed & Niclas Kings also serving as the producer of the song. Discussing the theme of the song with Andrea Simpson from Celebuzz, Brown described "Warrior" as, "about fighting for what you want even if the odds are against you... Pushing forward when others who fear you are trying to bring you down".[2] "Warrior" was released digitally via the iTunes Store on 27 September 2013, as the second single from Flashing Lights.[3] The track was serviced to radio on 14 October 2013.[4] Lyrically, Brown is asserting her toughness and dominance, stating "I am a fighter, it's in my DNA/step by step, and brick by brick, nobody stopping me...Strike like a tiger/I stand like a soldier, yeah/march like a champion!"
"Warrior" debuted on the Australian ARIA Singles Chart at number 32 on 12 October 2013.[5] After spending eleven weeks on the charts, the track peaked at number 11, staying there for one week.[6][7] "Warrior" also appeared on the ARIA Dance Singles Chart, peaking at number three in the top twenty.[8] The recording was certified triple platinum by the Australian Record Industry Association (ARIA), denoting 210,000 equivalent units sold in Australia.[5][9] The song later peaked at number 1 on the US Hot Dance Club Songs chart (Billboard), becoming her fourth number one on that chart.[10][11]
The music video for "Warrior" was uploaded to YouTube on November 5, 2013. It features Brown and her backup dancers dancing in various warlike soldier costumes, including one seen in which Brown is wearing what resembles Ancient Greek battlements. The video also flashes back and forth between Brown and her dancers and a close-up shot of a beating drum, accompanied by the lines "Gonna feel my blood running wild and young; Gonna dance, dance, dance to the beat of my drum/Like a warrior."[12]