Fourth-ranked Gauff, a 22-year-old American and two-time Grand Slam winner, advanced to Thursday's semi-finals, where she will face Kazakh star Elena Rybakina.
Gauff defeats Andreeva to reach US Open semi with Rybakina
Coco Gauff saved two match points to defeat reigning French Open champion Mirra Andreeva 2-6, 7-6 (9/7), 6-2 in a US Open quarter-final.
Rybakina will jump to world number one in next week's rankings after beating Chinese qualifier Zheng Qinwen 3-6, 6-1, 6-4.
Rybakina has a 1-1 career record against Gauff, winning a semi-final last month in Canada after Gauff won their only other meeting in Canada in 2022.
Fifth-ranked Andreeva, a 19-year-old Russian, won her first major title at Roland Garros but was foiled despite owning two match points in the second set tie-breaker.
Current world number one Aryna Sabalenka of Belarus and third-ranked American Jessica Pegula will meet in the other semi-final.
Gauff won all five prior meetings with Andreeva, including a victory on the way to the 2023 US Open title and another in this year's Rome quarter-finals.
Andreeva dominated the opening set, then denied Gauff's first break point chance of the day with a forehand winner and held in the fourth game to 2-2.
Gauff broke for a 4-2 edge when Andreeva sent a backhand long but the Russian broke back in the seventh game when Gauff sent a forehand wide.
Andreeva netted a forehand volley after two double faults to surrender a break in the eighth game but Gauff, serving for the set in the ninth game, netted a forehand for a fourth consecutive break as they battled into a tie-breaker.
Gauff saved two match points in the tie-breaker when Andreeva smacked forehands wide and long, then captured the set when Andreeva sent a forehand long then netted a forehand.
In the third set, Gauff broke for a 2-1 lead and seized a 5-2 edge when Andreeva netted a forehand to surrender a break. Gauff then held for the victory.
