Japan's Kei Nishikori advanced to his first ATP semi-final in more than two years by defeating South Africa's 50th-ranked Lloyd Harris 6-3, 7-5 on Friday at the Citi Open.

Nishikori had lost six consecutive tour-level quarter-finals, including one to Harris in March at Dubai, but this time dispatched the 24-year-old, who defeated Rafael Nadal on Thursday.