Kei Nishikori defeated Thiago Monteiro 4–6, 6–7, 7–5, 6–2, 6–3 in the first round of the Australian Open on hard court. As the clear pre-match favourite at 1.22 odds, Nishikori delivered the expected result, though Monteiro's competitive opening two sets—both decided by narrow margins—suggested genuine resistance. The Japanese veteran found his rhythm in the third set, breaking through at 7–5 before dominating the final two sets with increasingly commanding tennis. The comeback from two sets down showcased Nishikori's experience and mental resilience on a surface where he has historically performed well. The victory advances Nishikori into the second round and demonstrates his capacity to navigate tricky early-round opponents at a Grand Slam.