Serena Williams has lost in the US Open semifinals for the second year in a row. She was beaten 6-2, 7-6 (5) by the Czech Republic 10th-seed Karolina Pliskova.
Williams - who was clutching at her left hamstring occasionally in the second set - lost with a double-fault in the second set tie-breaker.
The loss means Williams won't be winning her seventh championship at Flushing Meadows or her 23rd major title overall - both would be Open-era records.
Williams' 3½-year reign at number one in the WTA rankings will also end. The US star will be overtaken on Monday by current number two, the German Angelique Kerber, who beat Caroline Wozniacki in two sets in Thursday's second semifinal.
A year ago, Williams' bid for a calendar-year Grand Slam ended when she lost in the US Open semifinals to unseeded Roberta Vinci of Italy.
The 24-year-old Pliskova (pictuted left) advances to her first major final.
For top-seeded Williams, whose 22 grand slam titles are tied with Steffi Graf, it was the second consecutive year she has lost in the semis at Flushing Meadows.
jbh/kl (AP, Reuters)