Christopher O'Connell defeated Cristian Garin 3–6, 7–5, 4–6, 6–1, 7–5 in the first round of the Australian Open on hard court on 14 January 2024. O'Connell, the pre-match favourite at 1.43 odds, held serve as expected despite a demanding five-set encounter. Garin, the underdog at 3.08, competed throughout and claimed the opening set decisively, then took the third to push the match to a decider. However, O'Connell's resilience showed in the second, fourth and fifth sets, where he broke through to secure the victory. The Australian's comeback from a set down twice underscores his ability to sustain intensity across the distance, a quality that will be tested further in the tournament's opening rounds.