Djokovic immediately rushed over to check if she was okay and placed his hand on her back as the judge struggled for air. After a few minutes she was able to get up and walked off the court.
Earlier, Gabriel Barbosa came off the bench to fire defending champions Flamengo to a 2-1 home victory over Fortaleza.
Dejan Lovren scored first for the visitors in the 18th minute, but Antoine Griezmann's close-range effort and Dominik Livakovic's own goal gave France the lead before the interval.
Leon are now a point clear of second-placed Cruz Azul, who will have the chance to regain top spot when they visit Atlas on Saturday.
Defending champion Egan Bernal also arrived with the leading group and was able to improve his overall ranking to second place.
Looking to hold onto their narrow lead, Slovakia played more defensively in the game's later stages, and were punished for their caution in the first minute of injury-time, when Ilay Elmkies equalized from Yonatan Cohen's through-ball.
However, seven of the players tested positive for COVID-19 a few days after their arrival in camp.
Marcelo remains in support as left-back, presuming that Madrid decide to cash in on Sergio Reguilon, while Alvaro Odriozola's return from loan should offer support to Carvajal.
The group testing sessions will include some advance-notice testing, where the main focus will be on building the profiles of athletes for the Athlete Biological Passport (ABP) program.
"It's going to be one of the young guys, I think, if you count Dominic Thiem as a young guy, as well. He obviously has a chance to win. Now I think it is the time where it gets really interesting. We'll see where we go from here," added the German.
"I managed to beat this milestone of 100 goals and now for the record (109)," said Ronaldo, who is only outscored by Iran's Ali Daei with 109 international goals. "It's step-by-step. I am not obsessed because I believe the records come in a natural way."