Serena receives apology

Singapore - Serena Williams has said on Thursday that she and her sister Venus have received a written apology from the head of the Russian tennis federation after he caused a storm by calling them the "Williams brothers".

Williams said Shamil Tarpischev, who has been fined $25 000 and banned for a year by the Women's Tennis Association over the remarks he made on a TV chat show, had "reached out" over the controversy.

"He has reached out to apologise to both myself and my sister," she said at the WTA Finals in Singapore, after her 6-1, 6-1 win over Eugenie Bouchard. "It was written. No, I did not speak to him."

Williams had earlier slammed Tarpischev's comments, which also earned a strongly worded rebuke from WTA chief Stacey Allaster and condemnation from Russia's world number two Maria Sharapova.

"His comments, I thought, were very insensitive, I thought they were extremely sexist as well as racist at the same time, and I thought they were in a way bullying," Williams said on Sunday.

Tarpischev, a vastly experienced coach and administrator, has also issued a public apology for his remarks but he insisted his "joke" did not merit the attention it has received.

The controversy cast an unwanted shadow over the start of Williams' Finals campaign, which remains hanging in the balance following her stunning 6-0, 6-2 defeat to Simona Halep on Wednesday.

Despite Thursday's strong recovery against Bouchard, the defending champion still needs Halep to win at least a set in her final group match against Ana Ivanovic if she is to reach the last four.

But Williams insisted she wouldn't "stress out" over her fate -- and may go and watch a Mariah Carey concert rather than see whether Halep can help her into the semi-finals on Friday.

Halep's decisive final Red Group round robin match with Ivanovic is scheduled to start at 7:30 pm in Singapore -- the same time that doors open nearby for the concert by American singer Carey.

"It's out of my hands. The last thing I'm going to do is stress out about it," said Williams. "If I don't qualify, you know, I'll be sad, I guess, but wasn't my year. I'm not going to fall out and die."

She said her schedule on Friday would involve a practice session and "then I will just relax and maybe go see Mariah Carey".

Williams' loss to Halep on Wednesday was her worst defeat since she was a title-less teenager. After responding in emphatic fashion, she said much credit lay with her coach, Patrick Mouratoglou.

"It wasn't just one thing. It was both tactically and mentally. And then I think his belief was really key, because I was feeling mighty low," she said.

"I was able to feed off this belief. I know that sounds weird, even though I've won so many titles, I still at some point feel like, 'Oh, gosh. Well, maybe I might not be able to do this or maybe I might not be able to do that'.

"Especially after a loss. Especially the way I performed yesterday. So I definitely don't think that I would've been able to survive today if it wasn't for Patrick. For sure."