Beijing - Favourite Juan Martin del Potro avoided the fate of third seed Grigor Dimitrov to surge into the quarter-finals of the China Open on Tuesday.
The towering Argentine top seed, enjoying one of the best seasons of his injury-blighted career, dismissed Russia's stubborn Karen Khachanov 6-4, 7-6 (7/4) in Beijing to make the finals of an ATP event for the first time since 2013.
The world number four will again be strongly fancied when he faces Filip Krajinovic of Serbia in the last eight.
Bulgaria's Dimitrov was on the end of a major shock, totting up nine double faults in a three-set defeat to Serbian qualifier Dusan Lajovic.
Lajovic meets Britain's fifth seed Kyle Edmund in the quarter-finals.
The 30-year-old Del Potro was imperious from the off, breaking the unseeded Khachanov in the first game of the match and then winning his own service game to love.
Del Potro, losing finalist at the US Open last month, finished off the first set with an ace to underline his superiority.
Khachanov, ranked 24th in the world, forced the second-set tie break with a break of Del Potro's serve but was always playing catch-up after going 3-1 down.
Del Potro sealed the match with his 11th ace.
Javier Mascherano, the Argentine international footballer formerly of Barcelona and now playing in China, was in the crowd to see his countryman and friend.
In the women's draw, number two seed Caroline Wozniacki rounded off a polished display with an ace in a 7-5, 6-3 victory over Petra Martic of Croatia.
The Dane faces Estonia's Anett Kontaveit in the last 16.
Seventh seed Karolina Pliskova of the Czech Republic set up a meeting against China's top player Wang Qiang.