InsideJapan News Network

Japan's teenage tennis star Kei Nishikori has caused a sensation by defeating the world number four David Ferrer.

The victory was secured after three hours and 25 minutes, reports the AFP press agency.

Mr Nishikori is only the second Japanese tennis player to reach the fourth round of a Grand Slam tournament in the modern era of the game.

Previously, Shuzo Matsuoka made it to the quarter-finals of Wimbledon in 1995.

Following his win, Mr Nishikori commented: "I still can't believe it I was playing great. This is the biggest win for me."

He also revealed that he almost suffered from cramp during the game and was spurred on by a desire to beat such a highly ranked player.

Mr Nishikori, who was ranked 281st in the world at the end of last year, will face the Argentinean Juan Martin Del Potro in the next round.