 Complete the following phrase:  Nadal retained his top ranking by reaching the semifinal. Federer lost in the quarterfinals to Kevin Anderson despite leading by two sets to love and having a match point in the third set. The semifinal match between Anderson and John Isner, lasting 6 hours 36 minutes, was the second longest mens singles match at Wimbledon and the third longest mens singles match in tennis history. Isner has thus played in the two longest matches in Wimbledon history the other one being the record-holding 