NEW YORK, (Reuters) – Marat Safin threw a protective arm around his little sister Dinara Wednesday after the Russian world number one was slammed for her wobbly performance in the first round of the U.S. Open.

Ever since Safina ascended to the top of the rankings in April, she has come under a barrage of criticism as she had yet to back up her standing with a grand slam title.

A mauling by Venus Williams in the Wimbledon semi-finals, where Safina won just one game, followed by Tuesday’s match in which she almost suffered the humiliation of becoming the first women’s top seed to perish in the first round of the Open has only served to give her detractors a louder voice.

But Safin, a former world number one himself, said people should just shut up and accept the WTA rankings.

“Everybody is hard on her why she’s number one. Is she a real number one or not?

“You open the page (of a newspaper and all you read about is), she made eight double faults, 43 unforced errors. She struggled, almost lost to (an) 18 year old,” former U.S. Open champion Safin said after he bowed out of the grand slam arena with a first-round loss to Austria’s Juergen Melzer.

“Who cares? I mean, she’s number one in the world. I have to protect my sister. The poor girl, she’s trying her best. She’s doing really well. She gets the attention, but not the kind of attention that a person deserves, especially when you’re number one in the world.”

Serena Williams was one of the most vocal critics of the system as she struggled to understand how she could be ranked second despite winning two majors this season. However, outside the slams, the American’s last tour victory was in April 2008.

Safina on the other hand has been rewarded by a system that values consistency rather than the quality of tournaments won.

Safin pointed out his sister, who has contested 15 finals in the past 12 months and won seven of them, was not the one to make up the rules and pleaded: “She didn’t do the ranking. Deal with that. Leave her alone.”