New York (AFP)

Serena Williams qualified Sunday for the quarter-finals of the US Open by logically beating Croatian Petra Martic (22) 6-3, 6-4, despite an alert at her right ankle.

"I said to myself, oh no, not again, I'm just starting to walk!", She said, referring to knee and back injuries that thwarted her 2019 season.

She will face Chinese Wang for a place in the semi-finals.

She dropped in the first set and twisted her right ankle. At next change of side, at 3-2 for her and service to follow, she was put a bandage.

"I wanted to compress it as quickly as possible," she said last year's finalist.

She reached the quarter-finals of the US Open for the 16th time and won the first of her six titles 20 years ago.

"I'm so old?" she exclaimed when asked what it was doing to her.

The 38-year-old, who will turn 38 on Sept. 26, is aiming for a seventh trophy at Flushing Meadows after 1999, 2002, 2008, 2012, 2013 and 2014, which would allow her to match the record of 24 Grand Slam titles held by Margaret Court.

© 2019 AFP