"She said congratulations. I told her thank you for everything that you did. I wouldn't be here without you. I always wanted to tell her that," the 15-year-old Gauff said after the match on Monday, reports Efe news.
The world number 301, the youngest player ever to qualify for Wimbledon in the Open Era, took out a player who is 24 years her senior, setting a record for the match with the biggest age difference between opponents at the grass-court event.
"Honestly I don't really know how to feel. That's the first time I have ever cried after winning a match. I don't even know how to explain how I feel," Gauff said.
Williams, a five-time Wimbledon champion, appeared to be getting back into the match at 4-4 in the second set, but Gauff did not falter and continued to put the pressure on.
"I definitely had to tell myself to stay calm, I had to remind myself that the lines are the same lines, the courts are the same size and after every point I told myself 'stay calm,'" Gauff said.
With this victory, Gauff, who had just 31 professional matches under her belt heading into Wimbledon, will move up to world No. 215 in the WTA rankings.
Up next for Gauff is Slovak veteran Magdalena Rybarikova, who took out No.10 seed Aryna Sabalenka, of Belarus, 6-2, 6-4 earlier in the day.
( With inputs from IANS )