Serena Williams loses No 1 rank after US Open exit

Serena Williams suffered a shocking defeat Thursday against Karolina Pliskova at the US Open semifinals, forgoing a chance to reclaim the title she lost last year.

The living legend and six-time U.S. Open champion was outplayed by 10th seed Karolina Pliskova of the Czech Republic, who will face Angelique Kerber in the finals after she beat Caroline Wozniacki.

With Thursday's matches in the books, Kerber is guaranteed to take the world's No. 1 ranking from Williams, who was knocked out of the Rio Olympic Games last month in the third round.

Coming off a hard-earned victory against 5th seed Simona Halep, Williams appeared set to capture her 23rd Grand Slam title and surpass another legend, German Steffi Graff as the all-time record holder.

But that is not how the cookie crumbled at Arthur Ashe Stadium.

Williams, 34, double faulted on match point and lost in straight sets 6-2 7-6 (7-5).

Pliskova beat the older Williams sister, Venus, in the fourth round of the tournament.

The defeat means Williams will have to make history. She also loses an opportunity to pass Graf for the number of weeks ranked No. 1 where they are tied at 186.

"Karolina played great today," Williams during at a post-game news conference. "I think if she had played any less then maybe I would have had a chance. So I think I wasn't at 100%, but I also think she played well. She deserved to win today,” she added.