The power players Sunday were on the women's side.
Worn down: Maria Sharapova was beaten in three sets.
However, the six hours and 44 minutes she clocked up winning those matches seemed to have sapped a little zip from her legs, and the unforced errors mounted on her exhausted racket in the second set.
Sevastova's smooth style contrasted with Sharapova's more mechanical ball-striking. The tournament directors, sponsors and fans have welcomed the game's most marketable female star and the tall Russian, who turned out in a black dress embedded with crystals for her Grand Slam return, has oozed glamour and gumption in NY.
Muguruza will play two-time Wimbledon victor Petra Kvitova in the night fourth-round match at Flushing Meadows on Sunday.
"I don't make the schedule", Sharapova retaliated.
Japan confirms North Korea has conducted 6th nuclear test
Hours earlier, Pyongyang claimed its leader had inspected a hydrogen bomb meant for a new intercontinental ballistic missile . Trump last month ramped up his rhetoric on North Korea, warning of " fire and fury " if it continued to threaten the U.S.
"Just competing, you know, being in that competitive environment".
"I think there are a lot of positives". All that matters to me is I'm in the fourth round.
"I made a decision to stop because it was depressing", Sevastova has said of her break.
On Day 1 of the tournament, Sharapova won a three-set thriller under the lights against No. 2 seed Simona Halep. It did turn out to be a pretty big deal in the match against Leonardo Mayer. Ultimately, Maria Sharapova - for it is she - could not deliver on the faith of American television and the compliance of the organisers, succumbing to the magic of Anastasija Sevastova who chipped, lobbed and sliced her way - some times switching hands - to an impressive win in three sets. He sprinted ahead from that point on, winning the match 6-7 (3), 6-3, 6-1, 6-4 in three hours and 16 minutes.
It hasn't been easy sailing for Nadal, or for that matter his perennial rival Roger Federer.
Venus' average rank of opponent through her first week was 93.
North Korea confirms hydrogen bomb test
One expert said the size of Sunday's detonation meant it was possible it could be a hydrogen bomb test. South Korea's Yonhap News agency says a magnitude 5.6 quake has occurred in North Korea.
The No. 9-seeded Williams is trying to get to her third Grand Slam final of the season.
In the women's section, Karolina Pliskova is slowly getting used to the view from the top. She has not lost a set and in four of her six sets she lost no more than one game. But still you have to beat her. Where the Latvian can turn the tables is with her variety and tennis IQ.
Sky Sports Tennis will have all the action from the US Open covered via our website www.skysports.com/tennis with our live blogs and updates throughout the fortnight as the Grand Slam year reaches its climax. In the second round, Rublev was up against seventh seed and the man in form Grigor Dimitrov.
In a freakish fourth-round contest, the Argentine reeled off the last five games after being treated for a leg issue to oust 16th-seeded Frenchman Lucas Pouille 7-6 (7-3) 7-5 2-6 6-2.
Carreno Busta won his third career ATP title in May on Estoril clay then reached his first Slam quarter-final at the French Open, where he retired against Rafael Nadal with an abdominal injury that kept him out of Wimbledon.
The 30-year-old Russian couldn't convert a key break point at 4-3 in the second set, and the Latvian captured momentum. This one will come against the resurgent Sloane Stephens. Keys and Alison Riske had set the record previous year, finishing the day's schedule at 1:48 am. Anastasia Rodionova and Ukraine's Nadiia Kichenok also went out, 4-6 6-2 6-1 against Ekaterina Makarova and Elena Vesnina.
Martin O'Neill disappointed with Republic of Ireland performance
That's what we have to do", said O'Neill. "We wanted to hold onto the lead but you can't hold on against technically good players. Leaders Serbia are now two clear at the summit after their 3-0 home victory over Moldova .