Japan's soon-to-retire Kei Nishikori moved within a win of the U.S. Open main draw Wednesday after beating 16-year-old American Michael Antonius 6-4, 6-4 in the second round of qualifying.The 36-year-old Nishikori went up 4-0 in the first set and 3-0 in the second before sealing the win with an ace in a commanding 1-hour, 16-minute match at Flushing Meadows, where he was runner-up in 2014."Managing to win in straight sets for the first time in a while makes me happiest," said Nishikori, who announced in April that he will retire at the end of the season.The former world No. 4 has been plagu…READ FULL ARTICLE