Stephens added to list of seeds to bow out

The shocks continued in the heat of New York yesterday as women’s defending champion Sloane Stephens became the latest big name to fall at the US Open.

In stiflingly hot conditions, the American went down 6-2 6-3 to Latvian Anastasija Sevastova, who is through to her first grand slam semi-final.

That result followed Roger Federer’s exit from the men’s event on Monday night.

The Swiss star fell 3-6 7-5 7-6 (8-6) 7-6 (7-3) to world No 55 John Millman.

Stephens’ exit means Karolina Pliskova is the only member of the top 10 remaining ahead of her lasteight clash with Serena Williams.

Stephens and Sevastova met at the same stage last year, with the American coming from a break down in the final set before winning on a deciding tie-break.

It was arguably the closest she came to defeat in her remarkable run, but this time the third seed could not extricate herself from her predicament.

Federer said he was relieved the match was over after struggling in the hot and humid conditions.

The match did not finish until nearly 1am but the temperature was still around 30C with extremely high humidity.

Australian Millman had never previously beaten a top-10 player, appeared to have even less chance of winning with Federer a set and a break up and holding two set points, but he somehow clawed his way back to clinch victory.

While Millman produced the performance of his life, Federer gave one of his poorest displays, struggling with all parts of his game and making 76 unforced errors.

Federer said: “For some reason I just struggled in the conditions. It’s one of the first times it’s happened to me.”

Juan Martin del Potro reached the semi-finals for the third time in the last five grand slams after coming through a gruelling battle with John Isner.

The two big men battered each other to near exhaustion in the humidity on Arthur Ashe but it was Del Potro who proved the stronger in a 6-7 (5-7) 6-3 7-6 (7-4) 6-2 victory that lasted three-and-a-half hours.

Junior matches were suspended yesterday because of the conditions.