Venus Williams said she was "killed by the grass" after taking a fall during her emotional Wimbledon return on Centre Court against Elina Svitolina.
Coco Gauff fell at the first hurdle at Wimbledon after going down to fellow American Sofia Kenin in a bruising contest on Court One.
Novak Djokovic eased into the second round of Wimbledon after beating Argentinian debutant Pedro Cachin 6-3 6-3 7-6 (4) amid farcical scenes on Centre Court.
Top seed Iga Swiatek made short work of her first-round opponent Zhu Lin at Wimbledon on Monday.
Roger Federer's achievements at Wimbledon will be celebrated in a special ceremony at the All England Club on Tuesday.
Rising superstar Carlos Alcaraz is eager to dethrone the indomitable Novak Djokovic at Wimbledon.