Federer pokes fun at himself after becoming oldest world number one

Amid all the plaudits after becoming the oldest world number one, Roger Federer showed he has a sense of humour as he poked fun at himself.

Swiss veteran Roger Federer is not only the world number one, but he is a funny guy too.

Federer, 36, sensationally reclaimed the ATP's top ranking after rallying past Robin Haase for a 4-6 6-1 6-1 victory to reach the Rotterdam Open semi-finals on Friday.

The 20-time grand slam champion, who celebrated a sixth Australian Open crown last month, will return to the summit for the first time since November 2012 when the rankings are updated on Monday, dethroning rival Rafael Nadal when the

Amid all the plaudits after replacing Andre Agassi as the oldest man to top the rankings, the evergreen star showed he has a sense of humour, poking fun at himself.

"Apparently I'm the oldest tennis player with a #1 ranking. Somebody might have mentioned that to me already but I had a hard time hearing," Federer wrote via Twitter.

Federer will face Andreas Seppi for a spot in the final.