Zheng Qinwen pulled off another remarkable win at the US Open on Monday, and then insisted there was nothing lucky about her progress to the quarter-finals after she downed Iga Swiatek in straight sets. The former world No 4 has been in such poor form for the past year, that she had dropped to 125th in the rankings and needed to come through qualifying just to reach the main draw. But as she had done in the previous round against Madison Keys, the Olympic champion battled back from 5-0 down in...