Oppressive heat continued to disrupt play at the Cincinnati Open on Monday, forcing France’s Arthur Rinderknech to collapse and retire from his third-round match against Canada’s Felix Auger-Aliassime. Tournament officials said on-court temperatures topped 32°C, with humidity above 50 %. Rinderknech received medical treatment after falling near the baseline while trailing 7-6(4) 4-2, attempted two more games, then conceded the contest and left the court with ice packs on his neck and legs. The sweltering conditions also framed a three-hour, nine-minute thriller in which world No. 1 Aryna Sabalenka edged Britain’s Emma Raducanu 7-6(3) 4-6 7-6(5). Sabalenka relied on her serve to extend her season-long perfection in tiebreaks to 18-0 and advance to the last-16, where she will meet Spain’s Jessica Bouzas Maneiro. The match featured a brief exchange with the chair umpire after Raducanu asked that a loudly crying child be removed from the stands, but play continued without delay. On the men’s side, top seed Jannik Sinner battled both Canadian qualifier Gabriel Diallo and a mid-match fire alarm, prevailing 6-2 7-6(6) to stretch his hard-court winning streak to 23 matches. Earlier, fourth seed Taylor Fritz and former champion Madison Keys progressed in straight sets despite a one-hour power outage blamed on overheated generators. Tournament organisers said additional cooling measures and shaded rest areas would remain in place as forecasts call for similar temperatures through the week.