NEW YORK (AP) A year after one of the most significant and stunning losses of Serena Williams' illustrious career, she's made it back to the same stage of the same tournament: the U.S. Open semifinals.
The stakes and opponent are different. Once again, there is history in the offing.
At Arthur Ashe Stadium in 2015, two wins shy of completing the first calendar-year Grand Slam in more than a quarter-century, Williams was upset in three sets by unseeded Roberta Vinci of Italy. At Ashe on Thursday night, two wins shy of claiming a record 23rd major singles title and earning a record 187th consecutive week at No. 1 in the WTA rankings, Williams faces 10th-seeded Karolina Pliskova of the Czech Republic.
Vinci never had participated in a Grand Slam singles semifinal. Neither has Pliskova, who hadn't even been past the third round at major until now.
The 24-year-old Pliskova grew up watching the Williams sisters play on TV and she already eliminated one in this tournament, beating Venus in a third-set tiebreaker after saving a match point in the fourth round.
Asked whether she expected to get some advice from her sibling before facing Pliskova, the younger Williams said: ''I'm sure she will tell me something. But I'll be there. I'll be ready tomorrow.''
Pliskova will be trying to become only the fourth woman to beat both Williams sisters at the same major, joining Martina Hingis at the 2001 Australian Open, Justine Henin at the 2007 U.S. Open, and Kim Clijsters at the 2009 U.S. Open.
But Pliskova, who leads the tour in aces this season, realizes what a daunting task awaits her against Williams.
''She's a big hitter and she can have 50 winners - and you cannot do much about it,'' said Pliskova, whose twin sister is also a tennis player. ''But I'm still going to hope that there is going to be some chance in the match where I can get my chance and be the one who is playing aggressive.''
The other women's semifinal Thursday is No. 2 Angelique Kerber of Germany against 74th-ranked Caroline Wozniacki of Denmark, a former No. 1 who is a two-time runner-up at Flushing Meadows.
Kerber, who is 7-5 against Wozniacki, has a chance to overtake Williams atop the rankings after the tournament.
''This would mean a lot to me,'' Kerber said. ''I mean, when I was a kid, I was always dreaming (of) being the No. 1. Let's see. I mean, there are still matches to go.''
Williams overcame a real challenge in the quarterfinals, her first of the these two weeks, by getting past No. 5 Simona Halep 6-2, 4-6, 6-3 with the help of 18 aces and by winning the point on 26 of her 32 trips to the net.
The sore right shoulder that developed in the days after the American won Wimbledon to tie Steffi Graf's Open-era mark of 22 major championships does not appear to be a problem any long.
''I feel OK. I'm not at 100 percent, but I'm OK,'' Williams said. ''Nothing to complain too much about.''
During the difficulties she encountered in the second set of her quarterfinal - Williams went 0 for 12 on break points - there never was the sort of emotional display she is famous for. A cracked racket, say, or screams of anger or self-encouragement.
''I was rather positive today, and that's not normal. I'm just going to go with it,'' Williams said with a smile.
Asked later to explain her mental state more, Williams replied: ''I was really rather calm today and not trying to be. I guess that's just how I got out of bed this morning. I definitely wanted to do some more `Come ons.' I don't know why. That's weird.''
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