NEW YORK, Aug 31 ― Madison Keys overcame a health scare in the second set to reach the last 16 at the US Open for a fifth consecutive year with a 6-3 7-5 win over fellow American Sofia Kenin yesterday.

The American 10th seed used a serving masterclass to breeze through the first set but her game noticeably dropped off in the second where she had her pulse and blood pressure checked while trailing 4-3.

But Keys, who fell to Sloane Stephens in the 2017 final and to eventual champion Naomi Osaka in last year's semi-final, returned to the court and eventually got the decisive break in the 11th game before serving out the match.

"Just not feeling 100% tonight but really glad I was able to get through in two (sets), it would have been a lot trickier if I had to go another set,” Keys said.

"This was definitely a test but I'm really happy I was able to mentally get myself up.”

Keys, who beat Kenin in a semi-final clash two weeks ago in Cincinnati, turned aside each of the eight break points she faced in the match, including a pair in the final game.

Up next for Keys will be Ukrainian fifth seed Elina Svitolina, who crushed Dayana Yastremska 6-2 6-0 earlier on Friday. ― Reuters