Two-time champion Rafael Nadal is through to the last 16 of Wimbledon with a straight-set win over Russia s Karen Khachanov. Spanish fourth seed Nadal took the first set in just 21 minutes and eventually won 6-1 6-4 7-6 (7-3) on Centre Court. Ninth seed Kei Nishikori is out after the Japanese lost in four sets to Spain s Roberto Bautista Agut. Marin Cilic is also through after comfortably beating Steve Johnson. Live coverage text and radio of the Championships Live scores and schedule BBC coverage times and channels Take on the legends in our interactive game Nadal broke the 21-year-old Khachanov s serve three times in the first set as he completely dominated his opponent. The second set was a tighter affair with Khachanov finally holding his serve but still being broken in the third game. Nadal had to save a set point in the third to force a tie-break but the French Open champion triumphed in two hours and 14 minutes. Victory means Nadal has not dropped a set in his past 10 Grand Slam matches winning 28 completed sets in a row. If he reaches the final then he will return to the top of the world rankings for the first time since June 2014. The 31-year-old will play Luxembourg s Gilles Muller in the fourth round who earlier beat Britain s Aljaz Bedene. Nishikori lost 4-6 6-7 (3-7) 6-3 3-6 to 18th seed Bautista Agut in three hours and 21 minutes on court three. Bautista Agut has never gone beyond the fourth round at a Grand Slam while Nishikori is yet to go beyond the last 16 at Wimbledon. Croatia s seventh seed Cilic who beat American Johnson 6-4 7-6 (7-3) 6-4 will face Bautista Agut in round four.