Updated

By Julian Linden

MELBOURNE (Reuters) - Roger Federer knows his incredible streak in grand slams is going to end one day. He just does not know when and hopes it will not be soon.

For his opponents, it offered some hope that he might finally lose some motivation. Far from it.

The 28-year-old Swiss remains as dedicated as ever and has hardly on his way to the semi-finals of the Australian Open, where he plays Frenchman Jo-Wilfriend Tsonga Friday.

It is the 23rd grand slam in succession where Federer has made it to the semi-finals.

The last time he failed to make the last four was at the French Open in 2004. No other player in history has appeared in more than 10 semis in a row.

Federer has breaking records for years but even he is impressed by his consistency.

"It's incredible looking back on how many years that is now," said the 15-times grand slam winner.

"For some reason I was just a bit worried I was not gonna make it this time in the semis.

"You always believe the streak is gonna be broken but I stopped thinking about it after the second round on and just started focusing on the tournament."

Federer has remarkably also appeared in 17 of the last 18 men's grand slam singles finals, including the last seven.

AMAZING RUN

"It's amazing," he said. "It's definitely one of the most incredible things I have in my resume."

Federer's record will provide little comfort for Tsonga, who lost the 2008 Australian Open final to Djokovic after coming through the other side of the draw.

That was the only time Tsonga has made a final but the Frenchman is unfazed, saying his relative inexperience was not an issue.

"Roger has experience because he won like 15 or 16 grand slams," the world No. 10 said. "But he won the first one without experience so I think at this level you never know what's going to happen.

"I have to play my best tennis because Roger is playing unbelievable...so it's going to be tough. But I will give everything and we will see."

The pair have split their previous two meetings and both players are in great form, Federer sweeping into the final after a four-set win over Nikolay Davydenko and Tsonga beating Djokovic in five sets.

Tsonga also won his previous match in five sets but the 24-year-old thinks he may have an edge in fitness over Federer.

"I don't know. I feel good. I won two tough matches. My two last match was tough, and I did it. Why not against Roger?" he said. "Maybe I'm stronger, physically stronger."

(Editing by Alastair Himmer)