Serena Williams is still on course for her 23rd Grand Slam title but she was made to work for her place by world No.5, Simona Halep, who literally played out her skin to try and stop the world No.1.
The first set was a breeze for Serena as she went 3-0 up in just six minutes.
Halep got on the board but could not stop the onslaught as she conceded the first set 6-2. The first two games of the second set was an all-out baseline battle as Halep staved off Serena to hold at 1-1, then broke – the first against Serena at this year’s US Open.
Serena made 25 unforced errors in dropping her first set of the tournament she fought off Halep’s determination to take the third set 6-3.
It is Serena’s ninth consecutive Grand Slam semifinal and the 33rd major semifinal of her career.
In the men’s draw, Andy Murray suffered a five-set loss to Kei Nishikori in what was one of the best matches so far at the 2016 US open.
At the beginning, it looked like it was going to be a stroll for the world No.2 as Murray won 6-1. After the match, Nishikori admitted that the first set for him was a case of no-show.
“It was tough to stay calm,” said Nishikori. “He started very well in the beginning, there were a lot of ups and downs in the match. But I’m very happy to win.”
The match lasted all of four hours on the Arthur Ashe Stadium court, Nishikori returns to the semi-final at Flushing Meadows since he first made it in 2014.
The fifth set was all Nishikori as he grabbed an early break to lead 2-0 but Murray fought back to take a 5-4 lead before a calmer Nishikori took the game in a tiebreak.
Murray would say he was not helped by a courtside disturbance early in the fourth set that he lost 6-1 and the fifth set was a display of hard baseline hitting that Nishikori prevailed on. Nishikori goes on to meet Stan Wawrinka in the semis.