After retiring through injury at the US Open, Rafael Nadal said he was simply in "too much pain" to continue his semi-final.
Juan Martin del Potro stands between Novak Djokovic and a third US Open title, and the Serbian has huge respect for the 2009 champion.
Chevy Chase was a notable spectator at the US Open on Friday, while Mike Bryan claimed yet another grand slam title.
Novak Djokovic produced a dominant display against Kei Nishikori to set up a US Open final with Juan Martin del Potro.
Rafael Nadal's US Open defence came to a sad end as he retired from his semi-final when trailing Juan Martin del Potro by two sets.
Defending champion Rafael Nadal needed a fifth-set tie-break to beat Dominic Thiem at the US Open, and conceded luck played a role.
Our latest US Open diary features amusing comments from Anastasija Sevastova and Juan Martin del Potro, who both won on Tuesday.
After beating John Isner at the US Open, Juan Martin del Potro joked about steering clear of his excitable friends in New York.
John Isner took the first set against Juan Martin del Potro, but the 2009 US Open champion won the next three to reach the semis once again.
Juan Martin del Potro is full of confidence heading into the final stages of the US Open.