Mona Barthel upset second-round favourite Ashleigh Barty at the 2017 Australian Open on hard court, winning 6–4, 3–6, 6–3. Barthel, the underdog at 2.42 odds against Barty's 1.65 favourite status, recovered from losing the opening set to dominate the final frame and secure a spot in the next round. The German's ability to break Barty's momentum after the second set proved decisive in the match. The result marked a significant scalp for Barthel and suggested Barty's early-tournament form was vulnerable to aggressive play.