Guy Den Ouden defeated Marton Fucsovics 7–6, 6–1 in the first round of the ATP 250 Rotterdam tournament on hard court on 11 February 2026, recording a significant upset against the pre-match favourite. Den Ouden, priced at 3.9, overcame the odds to eliminate Fucsovics, who entered as the clear favourite at 1.25. The Dutch player's composed performance in a tight opening set, decided in a tiebreak, set the platform for a dominant second set in which he broke serve decisively. The result marks a notable scalp for Den Ouden and represents a disappointing early exit for Fucsovics at a tournament where he would have harboured deeper ambitions.