This market refers to the tennis match between Matteo Arnaldi and Rei Sakamoto in the Japan Open Tennis Championships, originally scheduled for September 29, 2026 at 9:00PM ET. This market will resolve to 'Matteo Arnaldi' if Matteo Arnaldi advances against Rei Sakamoto. This market will resolve to 'Rei Sakamoto' if Rei Sakamoto advances against Matteo Arnaldi. If the match is canceled (not played at all), ends in a tie, or a winner has not been determined by October 13, 2026, 11:59 PM ET (14 days after the scheduled start), this market will resolve to 50-50. If the match begins but is not completed, and one player advances due to the opponent's retirement, default, or disqualification, this market will resolve to the player who advances. If the match ends in a walkover (player withdraws before the start and the other advances automatically), this market will resolve to 50-50. The primary resolution source will be official information from the ATP Tour. A consensus of credible reporting may also be used.