Zheng Jie v Serena Williams

Preamble: The knowing nods we all gave when Britain's last hope Elena Baltacha crashed out to wild card Zheng Jie are ancient history. Since then Zheng has overcome top seed Ana Ivanovic, 15th seed Ágnes Szávay, 18th seed Nicole Vaidisova and the fact that she's about 2ft 1ins tall to reach the semi-finals of Wimbledon and can no longer be overlooked. Zheng may not be in the same class when as Williams when it comes to power and shot-making ability, but she is surprisingly agile and incredibly dogged.

She simply does not give up on points and her ability to just keep returning the ball has driven many of her previous opponents to distraction. That's what she relies on and Williams will have to make mistakes for her to succeed. She remains the underdog, but, lest we forget, everyone was ready to write off Marion Bartoli before her semi-final against Justine Henin last year ...

Bear with me ... Doing the game-by-game on the first semi-final was thirsty work. I need a drink.