Alexander Zverev defeated Tallon Griekspoor 7–5, 6–0 in a round-robin match at the ATP 250 United Cup on hard court on 4 January 2026. The German dominated the second set entirely, breaking serve multiple times to secure a bagel and establish control of the tie-break first set, which he eventually won by two games. Griekspoor offered little resistance in the latter stages, unable to sustain the pressure required against Zverev's aggressive baseline game. The comprehensive victory underscores Zverev's solid form at the season's opening event and his continued dominance in hard-court conditions.