The USA Fed Cup team are one win away from defeating Belarus in their World Group II tie.

Christina McHale produced some of her best tennis in Saturday's opening match to defeat Anastasiya Yakimova 6-0 6-4 for the first point of the clash.

Yakimova was a late stand-in for world number one Victoria Azarenka, who was forced out of the tie due to a lower back injury.

Serena Williams followed McHale on to the court and, despite not being at her best, defeated Olga Govortsova, 7-5 6-0.

With one more win Sunday - when Venus Williams is scheduled to play her first match since August - the USA will advance to a World Group I play-off in April.

As for Azarenka, who won the Australian Open last Sunday, she will rest up in a bid to be fit for the WTA tournament in Doha, which starts on February 13.

She explained: "It has been a while and I have been trying to take [the injury] day by day.

"I had the pain since the Australian Open and was hoping to recover, but did not have enough time with all the flying I did. Unfortunately, it just didn't happen.

"It's disappointing, but health is the most important thing.

"It is frustrating to sit out, but what I did in Australia was very physical, so the body needs a little break."