Controversial Australian Nick Kyrgios swept aside Andreas Haider-Maurer in straight sets on Monday to set up a second-round clash with Kei Nishikori in the Shanghai Masters.
The outspoken Australian, who fired 13 aces and saved all five break points in a 6-3, 6-2 win over his Austrian opponent, has no illusions about the task ahead.
"Kei's one of the best players in the world right now," said Kyrgios. "He's got unbelievable returns. He's a great athlete. He's playing well. So I know what I have to do."
Slovak Martin Klizan beat local favorite Zhang Ze 7-6 (10-8), 6-2 and now runs into top seed Novak Djokovic, who is gunning for his ninth title of the year.
Croatia's Ivo Karlovic, who prevailed 6-4, 7-6 (8-6) over Frenchman Jeremy Chardy, also faces a formidable second-round opponent in 2009 runnerup Rafael Nadal, who lost to Djokovic in Sunday's China Open final.
American John Isner burnished his big-serving reputation with 20 aces in a 6-1, 6-2 romp against Adrian Mannarino, while Roberto Bautista Agut also had it easy against fellow Spaniard Guillermo Garcia-Lopez, who was beaten 6-2, 6-3.
American Steve Johnson cut short Italian Andreas Seppi's campaign with a 4-6, 6-1, 7-6 (7-2) win.