MELBOURNE, Australia — Amanda Anisimova upset 11th-seeded Aryna Sabalenka, 6-3, 6-2, to reach the fourth round of the Australian Open, her best showing at a major tournament.

Anisimova, a 17-year-old American, is the youngest player still in contention in the women’s draw at Melbourne Park and has dropped just seven games against seeded players in the last two rounds. She broke Sabalenka’s serve four times in the 65-minute match and fended off the only break point she faced.

Anisimova, who beat No. 24 Lesia Tsurenko, 6-0, 6-2, in the second round, had first-round exits in her two previous appearances in the main draw of major tournaments.

Sabalenka won the title at Shenzhen to start the season and reached the fourth round at last year’s U.S. Open.