Mariana Duque Marino defeated Oceane Dodin 6–1, 5–7, 6–2 in the first round of the 2015 US Open on hard court. Duque Marino, the pre-match favourite at odds of 1.55, delivered a composed performance despite a competitive middle set in which Dodin mounted a brief challenge. The Colombian secured the opening set convincingly before Dodin levelled the match by taking the second in a tiebreak situation. Duque Marino reasserted control in the decider, closing out the encounter with a dominant third set to advance. The victory consolidated her position in the draw and marked a solid opening to her Grand Slam campaign.