Dominic Calvert-Lewin's 16th minute header put Everton ahead but Brighton equalized through Neal Maupay after a Jordan Pickford error.
"It's been long ride definitely. Everything came to my mind when I had my whole family, people who I loved to help me through the tough, tough time," said Kvitova. "I was just playing in the Philippe Chatrier, it was such nice to win the match and to be in the quarterfinal."
Inner Mongolia will meet Shandong on Sunday, while Hebei will face Shanxi on Tuesday. Enditem
The Czech player fired 23 winners in the match in which she converted four of her nine break points. Despite missing a chance of serving for the win in the eighth game of the second set at 5-2, she clinched it when opportunity appeared again in the tenth to wrap up the victory with a love game.
The Spaniard, who is seeking his 13th title at Roland Garros, defeated Sinner 7-6 (7-4), 6-4, 6-1 to set up a rematch with Diego Schwartzman on Friday.
"We found several problems during the tournament and we will strengthen training in the future," he added.
Next up for Kvitova is Germany's Laura Segemund, who dispatched Spaniard Paula Badosa 7-5, 6-2 to advance. Enditem
Cadiz's win in Bilbao means it has won its two away matches this season, but lost its two home games and it has another difficult task when it entertains a Granada side that qualified for the group stage of the Europa League on Thursday night.
"I did not want to travel far and decided to enjoy my vacation in a more leisurely way," she said. "Kart racing helps me releave the pressure of work."
Cordoba has scored two goals in three Bundesliga matches this season following his September move from FC Koln.
Eibar has just one point from four games and Jose Luis Mendilibar's team travels to Real Valladolid after seven days which has seen them lose home games to Athletic Bilbao and newly-promoted Elche.