Christopher O'Connell defeated Valentin Royer 6–4, 4–6, 7–6 in the first round of the ATP 250 Rotterdam tournament on hard court on 9 February 2026, in an upset victory against the pre-match favourite. O'Connell, ranked lower in the betting odds at 2.07, overcame Royer's opening-set dominance to force a decisive third set, which he secured in a tiebreak after dropping the second frame. The Australian's ability to recover from a set down and convert the tiebreak proved decisive in a competitive encounter. The result represents a valuable scalp for O'Connell as he advances to the second round.