Kammala jumla mai zuwa: A taron Diamond League a Paris a ranar 6 ga Yuli 2012, Greene ya gudu mafi kyau na 47.84 seconds a kammala na biyu ga Javier Culson don matsawa kusa da rikodin Birtaniya a cikin 400m shinge. An zabi Greene ya zama kyaftin din tawagar 'yan wasa na Burtaniya don wasannin Olympics na London na 2012, a matsayin daya daga cikin wadanda aka fi so don lashe lambar yabo. A zagaye na farko na 400 m shinge Greene ya lashe zafinsa a 48.98s, lokaci mafi sauri na zagaye. A cikin wasan kusa da na karshe Greene ya gudu a hankali, ya gama na huɗu kuma kawai ya cancanci zuwa wasan karshe a matsayin mai saurin rasawa. A wasan karshe Greene ya gama na huɗu a bayan zakaran gasar Olympics ta 2004 Félix Sánchez, ya ba da mamaki ga Ba'amurke Michael Tinsley da Javier Culson, yana gudu a hankali fiye da yadda ya yi a wasan kusa da na karshe. Bayan tseren Greene ya yarda da babban abin takaici, kuma ya zargi tsangwama ga horo da ya haifar da raunin gwiwa a cikin hunturu. Har ila yau, Greene ya gudu a wasan karshe na
4 × 400 mita relay, yayin da tawagar Burtaniya ta kammala a matsayi na hudu, kawai 0.13 seconds daga lambar yabo.