The following month, she won her second WTA title at the Silicon Valley Classic, defeating Daria Kasatkina in three sets. The Silicon Valley Classic win marked her first WTA 500 title. As a result, she reentered the top 30 at world No. 28, on August 9, 2021. She then continued her win streak at the Canadian Open. She beat Jil Teichmann in the first round and then went on to defeat sixth seed Simona Halep in the second. Her 12-match win streak eventually came to an end in the third round, after losing to compatriot Jessica Pegula, in three sets. At the US Open, she reached the third round for the first time after defeating former world No. 6, Carla Suárez Navarro and Kaja Juvan. She then lost her third-round match to Aryna Sabalenka, in straight sets. In her next two tournaments, Collins reached the quarterfinals in Chicago and the third round in Indian Wells before concluding her season in Linz, where she was forced to retire in her semifinal match against compatriot Alison Riske due to a shoulder injury. Nonetheless, Collins finished the year ranked inside the top 30 for the first time, at No. 29. 2022: First Grand Slam final, top 10 debut, American No. 1, US Open fourth round At the Australian Open, Collins reached the semifinals for the second time, after defeating 19th seed Elise Mertens to become the third American woman in the quarterfinals. It was the second year in a row that three Americans have featured at this stage of the tournament. In the quarterfinals, she beat Alizé Cornet in straight sets. She defeated Iga Świątek also in straight sets in the semifinals to advance to her first Grand Slam final, where she faced world No. 1, Ashleigh Barty. Świątek said that Collins hit the,"...fastest balls I have ever played in a match." In the final, Collins lost in straight sets despite being 5–1 up in the second set. As a result of her performance, Collins made her top-10 debut and became the American No. 1 female player. At the French Open, she lost to fellow American Shelby Rogers, in straight sets, in the second round. In Wimbledon, Collins lost in the first round to Marie Bouzková, in three sets. At the same tournament, partnering Desirae Krawczyk, she reached the quarterfinals for a second time and then the semifinals for the first time at