That set up a rematch of last year's French Open title match, in which Nadal claimed a four-set win, although a round early this time. When they meet in Friday's semifinals it will be the 35th time they will have played each other. Nadal, who beat Djokovic in the 2008 French Open semis, holds a 19-15 edge in the series.
The other semifinal, which was determined Tuesday, sends fourth-seeded David Ferrer against French favorite son Jo-Wilfried Tsonga, the No. 6 seed who beat Roger Federer in the quarterfinals. Both are looking for their first Grand Slam titles.
Nadal improved to 10-0 in career matches -- 22-0 in sets -- against Wawrinka, the No. 9 seed. Nadal had just 17 unforced errors and won 70 percent of the points on serve. Wawrinka managed one break -- leveling the second set at 3-3 -- but Nadal broke right back with the help of three of Wawrinka's 40 unforced errors.
Djokovic dropped just 15 points on serve. He had five breaks on the day, including breaks that had Haas playing from behind throughout the third set. Haas managed two break chances and converted them both in the set, but Djokovic finished off a 14-point break in the 11th game and served out at love to head into the semifinals.
Friday will mark the 12th consecutive major tournament event in which Djokovic reached the semifinals. He needs a French Open title for the career Grand Slam. Nadal is seeking a record eighth French Open title. He's been a finalist in eight of the last 10 majors in which he's played.
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UPI Sports Results for September 20, 2014