SHANGHAI, Oct. 11 (Xinhua) -- World No. 1 Rafael Nadal battled past 8th seed Stanislas Wawrinka of Switzerland to set up a Juan Martin del Potro semifinal clash at the Shanghai Masters tennis tournament while defending champion Novak Djokovic will face Frenchman Jo-Wilfried Tsonga in the other one.
Nadal had to take the second tiebreak in two days as the Spaniard needed one hour and 14 minutes to close the opening set and after that the world No.1 never looked back, winning the quarterfinal at 7-6(10), 6-1 on Friday.
He will face up against 6th seed Del Potro of Argentina, who beat 15th seed Nicolas Almagro of Spain 6-3, 6-3 in an earlier quarterfinal.
Del Potro is one match win away from qualifying for the Barclays ATP World Tour Finals after he reached the semifinals.X He beat Almagro for the second time in as many weeks with a 6-4, 6-3 win in 72 minutes. The pair met in the Rakuten Japan Open Tennis Championships semifinals last week.
The 25-year-old Del Potro won 85 per cent of his first service points and committed just eight unforced errors.
"I played very well today, very solid," said del Potro, who has overcome a fever.
"I played aggressive. I hit my forehand very well. I like the way I played today. I just want to keep improving [and] keep going far in this tournament."
Defending champion and top seed Djokovic survived a scare against flamboyant Frenchman Gael Monfils to reach the semifinals.
The 26-year-old Djokovic defeated Monfils 6-7(4), 6-2, 6-4 and fired four aces during the match, which lasted two hours and 23 minutes. He won 80 per cent of first serve points.
"It was a tough match today, a tough battle," said Monfils. "I'm still happy. I haven't practiced much before here. To come here (and play) strong was good. He is one of the best players in the world, and I have no shame today... I'm already looking forward for 2014."
Tsonga moved to within 135 points of eighth placed Roger Federer in the ATP Race To London after the Frenchman advanced to the semifinals with a 6-2, 6-3 win over German Florian Mayer in 65 minutes.