Matteo Arnaldi defeated Novak Djoković 6–3, 6–4 at the Madrid Masters on clay in the first round, pulling off a significant upset against the pre-match favourite. The Italian, who carried odds of 3.93 against Djoković's 1.28, controlled both sets with consistent tennis and superior court positioning on the red clay. Djoković, seeded high and expected to advance comfortably, struggled to impose his usual rhythm and failed to find the solutions needed to break Arnaldi's serve and dictate play from the baseline. The straightforward nature of the scoreline underscored Arnaldi's dominance in the encounter. The result represents a career-defining victory for the 23-year-old and raises questions about Djoković's form and readiness on the Madrid clay surface this season.