Serena Williams has predicted that it will not be long before a teenager wins a Grand Slam tournament.

A number of teenagers have been impressing at the Australian Open this week, including Britain's Laura Robson and Americans Sloane Stephens and Madison Keys.

Williams, who won the US Open and French Open when she was just 17, says that it is a matter of time before these women start to challenge the top players.

"I think it will happen again, probably soon," said Williams.

"I think if the person is strong enough and tall enough, or short, but strong physically and mentally strong. It's completely possible.

"The game has changed but when I was 17 I was playing some pretty good tennis, as well as [Martina] Hingis and other teenagers who won. The game is definitely more physical."

Williams is due to play Maria Kirilenko in the fourth round today and admitted that she will need to be at her best to beat the number 14 seed.