Peyton Stearns defeated Amanda Anisimova 6–2, 2–6, 7–5 in the first round of the Madrid Masters 1000 on clay on 25 April 2025, securing an upset victory against the pre-match favourite. Anisimova, who entered as the odds-on favourite at 1.36, struggled to maintain consistency across the three sets. Stearns, trading at 3.37, took the opening set decisively before Anisimova levelled the match with a commanding second set. The decider proved pivotal, with Stearns edging a tight final set to seal the breakthrough win on the Spanish clay. The result marks a notable scalp for Stearns at a premier hard-court equivalent event and suggests momentum heading into the second round.