Research indicates that encouraging translanguaging can enhance learning in a range of contexts. However, there are few studies examining translanguaging for learning among newcomers in science education. This case study fills this research gap by examining in what ways a newcomer to the school uses translanguaging practices with his classmate to participate more fully in a linguistically diverse physics classroom, where neither the teacher nor a majority of the students share the same home language. The data comprises transcriptions of video and audio recordings and photographs from nine physics lessons (students aged 14-15 years). Translanguaging practices were identified and analyzed from a sociocultural perspective. Benito, the newcomer, spontaneously used English, Swedish, Spanish and Portuguese and prior knowledge in creative ways in interactions with his classmate during pair work, something that was not possible in whole class instruction. Multilingual peer dialogue, multilingual private speech and the use of multilingual artifacts increased learning opportunities. Moreover, Benito and his classmate Edin engaged in exploratory talk and demonstrated metalinguistic awareness. This study indicates that teachers who actively facilitate the use of students' multiple linguistic resources for sensemaking can contribute to a more egalitarian education and increase opportunities for learning in linguistically diverse classrooms.