Damir Dzumhur defeated Stéfanos Tsitsipás 6–4, 1–6, 7–5 in the first round of the ATP 250 Rotterdam tournament on hard court, pulling off a significant upset over the heavy pre-match favourite. Tsitsipás, priced at 1.17 to prevail, struggled to maintain consistency after taking the second set decisively; Dzumhur, a 5.63 outsider, capitalised on the Greek's loss of rhythm to edge a tight decider and secure passage to the next round. The Bosnian's comeback from a set down demonstrated resilience and tactical adjustment, while Tsitsipás's inability to close out the match raised early-season questions about his consistency on faster courts.