The Japanese player and her women’s doubles partner Aldila Sutjiadi were defaulted during their third-round clash with Marie Bouzkova and Sara Sorribes Tormo after Kato accidentally hit a ball girl with a ball.
The 28-year-old was allowed to continue in mixed doubles with German partner Tim Puetz and, back on the same court, the pair defeated Brazilians Luisa Stefani and Rafael Matos to reach the semi-finals.
There has been a lot of support for Kato since the incident from within the locker room and, as the crowd gave her and Puetz a prolonged round of applause, the Japanese player began to cry before being consoled by her partner.
Kato, who apologised on Twitter on Sunday evening, was in tears again in the press room and had to briefly leave her press conference before answering questions only in Japanese.
It is believed she has appealed against the disqualification in the hope of keeping her prize money and ranking points, which would normally be forfeited in such situations.
Puetz said: “I think, first and foremost, we’re all, including Miyu, happy that the ball girl is OK, because obviously she got hit. It’s a little girl on Court 14. For them they’re very excited to be there. I think you saw she was distraught.
“Besides that, I’m sure Miyu feels terrible about what happened. This was just very unfortunate for everyone, especially for her and the girl.”
Kato was returning a ball to the other end of the court after a point had finished but the ball girl reacted too late and it struck her on the neck.
The umpire initially gave a warning but, with Bouzkova and Sorribes Tormo pointing out the distress of the ball girl, the supervisor and referee were called and, after lengthy discussions, opted to default Kato and Sutjiadi.
The decision has drawn widespread criticism from within tennis, but Puetz had sympathy for the officials, saying: “All they see is a crying ball girl who got hit with a ball. In that moment, to make that decision is very difficult.
“While I don’t necessarily agree with it, I think I can understand how you would get to that decision. It’s much easier now looking at the pictures and then comparing to some other instances in the past years. Yeah, I think it’s very easy to say, ‘No, she should not have been defaulted’.”
Bouzkova and Sorribes Tormo have faced heavy criticism on social media for appearing to try to force the default, but the Spaniard insisted they did nothing wrong.
“It’s a very bad situation that happened yesterday,” said Sorribes Tormo. “Also, for Marie and for me, it’s tough to have all this kind of things that people are saying.
“It’s not easy because the only thing we’ve done yesterday was going to the referee and explain to him what happened.
“So, first of all, we were saying that the ball kid was crying because we were scared, because we were, ‘Oh, something happened’. Then we were saying that the ball was direct because he didn’t see the ball.
“All the rest, the decision was taken by the supervisor, and I think it’s not our thing or we haven’t done anything bad.”
Puetz now hopes Kato can write a happier ending to her fortnight at Roland Garros.
The German said: “I was happy yesterday when we got the call that we will be allowed to play mixed. Not because I care too much about the mixed, it’s just because hopefully she can kind of move on.
“I’m happy that we can still play a couple of matches here and just hopefully add some good memories to kind of get over it as well instead of just leaving Paris with that really crappy feeling with what happened yesterday.”