NEW YORK (Reuters) - A crowd gathered to watch world number one Rafael Nadal warm up in Arthur Ashe Stadium on a cool and windy Friday at the U.S. Open, ahead of his semi-final showdown with Argentine Juan Martin del Potro later in the day.
Nadal has faced little adversity at the tournament so far, dropping just two sets in his five matches and blowing out 19-year-old Russian Andrey Rublev in straight sets to reach the semi.
Twenty fourth-seeded Del Potro has had a rockier road, having had to fight off two match points and battle back from two sets down to defeat sixth-seeded Dominic Thiem in the fourth round in an instant classic before defeating third seed Roger Federer in the quarter-finals.
Big-serving South African Kevin Anderson was spotted on a practice court stretching his 6-feet 8-inches (2.03 metres) frame as he prepares to meet the other Spaniard in the semi-finals, Pablo Carreno Busta.
Anderson brings a 2-0 head-to-head record against the number 12 seed, who has quietly moved through the draw without dropping a set in five matches.
Earlier in the day, Dutchman Jean-Julien Rojer and Romania's Horia Tecau won the men's doubles title after beating Spaniards Feliciano Lopez and Marc Lopez 6-4 6-3.
The number 12 seeds hit 41 winners between them and made just seven unforced errors as they romped to the title in just under an hour and a half.
(Reporting by Rory Carroll; Editing by Hugh Lawson)