Roger Federer of Switzerland returns a shot during his men's singles tennis match against Gael Monfils of France at the Shanghai Masters tennis tournament in Shanghai, Oct 10, 2013. [Photo/Agencies]

SHANGHAI - Former world No 1 Roger Federer was ousted by Frenchman Gael Monfils at the third round while heavy favorites Rafael Nadal and Novak Djokovic both get through to the last eight at the ongoing Shanghai Masters on Thursday.

Federer won a tense tiebreak of the second set but still slumped to a 6-4, 6-7(5), 6-3 loss to Monfils after two hours and nine minutes.

Federer, 32, is battling to qualify for the ATP World Tour Finals for the 12th consecutive year.

"It was one of those matches that could have gone either way," said Federer. "I think I was a little lucky in the second set to get back, to be quite honest. I played a solid tiebreak."

"I had chances early on in the third set I think to make something happen. He kind of recovered, then started to serve a bit better again towards the end of the third set, which made it difficult for me. It's a bit of an up and down performance for me, " the fifth seed added.

When asked whether Andy Murray's withdrawal from playing at the ATP World Tour Finals increased his chances of qualifying, Federer said: "I hope I don't have to rely on it. If I have to, I have to. But that's not really what I want.

"I'm just going to focus on trying to play well. I'm just going to try to have a good tournament in Basel and Paris. In the end, if I get the invite, I'll be there."

Forty five minutes after losing to Monfils, Federer returned to the doubles court.

Gael Monfils of France returns a shot during his men's singles tennis match against Roger Federer of Switzerland at the Shanghai Masters tennis tournament in Shanghai, Oct 10, 2013. [Photo/Agencies]

But he ended up losing his second round doubles with Chinese hopeful Zhang Ze. Fifth seeds Ivan Dodig and Marcelo Melo scraped through 6-1, 1-6, 10-8 in 53 minutes.

"Roger just finished his singles match," said Zhang. "I should have given him more support. But we lost the first one too quickly. In the second set, both of us were a little bit calmer than in the first set because it was our last chance. But when it came to the tiebreak, a lot of times it's all about luck."

Earlier, ATP World Tour Finals qualifier Ferrer also lost at the round of 16, beaten by German Florian Mayer 6-4, 6-3 in just 81 minutes.

Mayer snapped a four-match losing streak against the Spaniard and the victory is his first Top 10 win of the year.

Mayer will in the quarterfinals take on Frenchman Jo-Wilfried Tsonga, who broke a two-match losing streak against Nishikori Kei with a 7-6(5), 6-0 win.