Updated

Shanghai, China (SportsNetwork.com) - Novak Djokovic won his semifinal match Saturday at the Shanghai Masters, but Juan Martin del Potro upended Rafael Nadal in the other to deny a matchup of the world's top two players in the final.

The top-seeded Djokovic earned a 6-2, 7-5 victory over France's Jo-Wilfried Tsonga in Saturday's opener, but del Potro just overwhelmed the second-seeded Nadal with a 6-2, 6-4 upset in the nightcap.

Djokovic beat Nadal last week in the final at the China Open in Beijing, ending a three-match losing streak to the super Spaniard -- a stretch that included a setback in the final at the U.S. Open. It was his first title since beating Nadal for the Monte Carlo crown in April.

The Serb, who was supplanted atop the ATP rankings this week by Nadal, will try for his fifth title of 2013 and his second straight at this event. He knocked off Andy Murray for last year's Shanghai crown.

Sunday's meeting against del Potro will be a matchup of last week's tournament winners. As Djokovic was winning in Beijing, del Potro was working on his third title of 2013 with a triumph in Tokyo.

The Argentine star also won in Rotterdam and Washington earlier this year. He also reached the final at Indian Wells, beating Djokovic in the semifinals before falling to Nadal in the championship match.

Saturday's win not only avenged the Indian Wells loss to Nadal, but it also guaranteed del Potro a spot in the season-ending ATP World Tour Finals.

Del Potro was in command right from the start, winning the first four games of the match. He broke twice in that span and broke again for a 2-1 lead in the second set. Not once did Nadal break serve in six opportunities.

Nadal was trying for his 11th title of 2013 and failed to reach a final for only the second time in 15 events this year. The only other such occurrence came at Wimbledon in a shocking first-round loss to Steve Darcis.

The sixth-seeded del Potro will carry a finals mark of 16-6 into Sunday's match. The 2009 U.S. Open champion has never won a Masters title.

Djokovic has a record of 14-10 in Masters finals and is 38-21 overall in title matches. He dominated Saturday with five breaks of serve, but did have his serve broken once in each set.

The six-time Grand Slam champ is 9-3 lifetime against del Potro, including a five-set victory in the Wimbledon semifinals this summer. Prior to del Potro's win in the Indian Wells semifinal, Djokovic came away with a straight-set win over del Potro in the Dubai semis.

Sunday's winner will earn $730,000.