Karolina Pliskova's eight-week run as world number one ended Wednesday with a US Open quarter-final loss, the Czech standout saying nothing has changed for her after so short a reign.

Top seed Pliskova, last year's US Open runner-up, fell 7-6 (7/4), 6-3 to US 20th seed CoCo Vandeweghe, missing another chance to capture her first Grand Slam title.

"I don't care. I don't think something is going to change if you are number two. I don't see any difference between this. So for me, no changes," Pliskova said.

"I was there for a few weeks. Maybe if you are there for one year, it's different. But like this, not."

Being among the number ones without a Slam crown to show for it in her career isn't a criticism Pliskova takes to heart.

"There's always going to be somebody who says something. I just don't care about this," she said.

"I didn't choose to be at this position where I am now, so hopefully I have many more chances. There is many more Grand Slams to come, so I believe I can win one."

Pliskova said she felt the pressure this week on the New York hardcourts.

"I was not playing my best tennis this tournament. Still made it to quarterfinals, which is pretty good. Just happy that I at least did this," Pliskova said.

"This pressure, what I had here this tournament, it was something new for me. So I never felt like this before. I was never actually defending the final of a Grand Slam. So it was totally different. Maybe I'm going to feel better in the next Grand Slams."

Pliskova's defeat before the final assured she will be overtaken atop Monday's rankings by Spain's Garbine Muguruza, who won her second Slam title in July at Wimbledon and took the last major US Open tuneup in Cincinnati.

Muguruza, who lost in the fourth round of the US Open to Czech 13th seed Petra Kvitova, becomes the 24th woman to top the rankings in WTA history.

"No. 1 Very happy!! Believe. Dreams come true. Thanks all! Love you," Muguruza tweeted after Pliskova's loss.

Pliskova's reign came with long-time world number one Serena Williams absent while pregnant. The 23-time Grand Slam champion gave birth to a baby girl last week and says she plans to defend her title next January in Melbourne.

Pliskova admitted she liked her chances when she saw her draw.

"I had quite high expectations and I knew I had a quite OK draw, so there was nobody unbeatable for me. Even this match today was not without chances, so maybe I put too much expectation on myself," she said.

"Sometimes there's not much you can do. Just happy this tournament is over now."

Source: AFP