WASHINGTON -- Rapidly improving Wang Yafan of China moved into the round of 16 at the Miami Open for the second straight year, after her Sunday's straight-set win over No 25 seed Danielle Collins of the United States gave her a second consecutive win over a seeded player in the tournament.

In the first meeting between the two players, it was 24-year-old Wang who eliminated last year's semifinalist Collins 7-5, 6-1 in one hour and 38 minutes, breaking the American's serve six times out of 13 break points.

"The first time playing Collins, and she played good. I know she had a good Australian Open, making semifinals there," Wang said after her win. "I didn't think too much, just focused, played my tennis, and that's it."

In the second round, Wang upset No 6 seed Elina Svitolina of Ukraine to register her first top 10 victory in career.

World No 50 Wang carried on her success in Miami as she reached the fourth round as a qualifier last year. "Last year, I played four rounds here," Wang said. "So I'm very happy and I want to play maybe better next match."