US Open: Serena Williams is inspired by rival Errani

The Italian had never been beyond the third round of a grand slam in singles before this year but she began the season by making the quarter-finals at the Australian Open and then made it all the way to the French Open final.

In New York she has showed more of the same form, beating sixth seed Angelique Kerber in the fourth round and then  doubles partner Roberta Vinci in the quarter-finals.

In an era of tennis dominated by power, the success of 5ft 4½in Errani is a welcome sight, although it would be a huge surprise if she made it any further.

Williams has won all three of their previous meetings – none of which have come in the last three years – but the title favourite has nothing but respect for her opponent.

“She’s playing well,” said Williams. “The final of Roland Garros and now semis here, potential final. I can’t underestimate her. It’s not by luck she’s been doing so well. She’s a great fighter and has a great attitude and believes. I think when you have such self belief then you can do anything. I love her attitude. I’m inspired by it actually.”

The other singles semi-final sees world No 1 Victoria Azarenka take on third seed Maria Sharapova, with both looking to win a second slam title of the season. Azarenka thrashed Sharapova in the Australian Open final before the Russian completed her career grand slam by beating Errani to win the French Open title in June.