Gauff has fared well on clay so far this year, reaching back-to-back finals in Madrid and Rome where she missed out on the titles to Aryna Sabalenka and Jasmine Paolini respectively.
A nervy start saw Gauff and Keys trade early breaks but Keys settled quickly as her rival continued to flounder, opening up a 4-1 lead.
To Gauff’s credit, she fought her way back into proceedings and held set point, but Australian Open champion Keys came through in the tie-break.
Unforced errors started to creep into Keys’ game during the second set and she quickly found herself on the backfoot at a double break down.
But just as Gauff had in the first set, Keys cancelled out the advantage, only for her opponent to level the match with another break and a hold.
Gauff had conceded nine double faults across the opening two sets but it was Keys who finished the match with 60 unforced errors off her racquet, compared to Gauff’s 41.
That ultimately proved to be the difference as Gauff, having finally found her serve, raced through the deciding set.
It is the third time Gauff has beaten Keys in six meetings and marked the first time she has beaten the 30-year-old on clay.
Gauff has lost to the eventual winner on each of her last four appearances at the French Open and if she can get through the semi-finals will face either defending champion Iga Swiatek or world number one Aryna Sabalenka in the final.