The 2008 winner Andy Roddick was sent packing in his opening match at the China Tennis Open by South African Kevin Anderson, joining the eighth seed Alexandr Dolgopolov in making an early exit.
There was also the high-profile withdrawal of Gael Monfils with a knee injury, the Frenchman saying he will also miss next week's Shanghai Masters.
Monfils, who lost in the Bangkok semi-finals at the weekend to Donald Young, was to have started as second seed in Beijing behind compatriot Jo-Wilfried Tsonga.
Roddick, the sixth seed in the Chinese capital, was comprehensively beaten 4-6 5-7 by Anderson, who blasted down his eighth ace for match point and triumphed on his second winning opportunity.
Dolgopolov fell 1-6 6-1 0-6 to Italian Flavio Cipolla in a topsy-turvy clash.
Croatia's former top 10 regular Marin Cilic, now 25th in the world, defeated China's Wu Di 6-2 6-0, while Spain's Feliciano Lopez put out Turk Marsel Ilhan 6-2 7-6 (8-6).
Spaniard Fernando Verdasco beat Michael Llodra of France 6-2 6-4.
Florian Mayer of Germany, playing his first match since winning the clay Bucharest title eight days ago, made a successful change to the hard courts, taking out Spaniard Albert Ramos 6-2 6-4.
Women's holder Caroline Wozniacki survived a tough challenge to begin her title defence, with the top seed stretched to the limit in a win over Lucie Hradecka, 3-6 6-0 7-5.
In other first-round matches, Zheng Jie earned a home win as she beat Alberta Brianti 4-6 6-1 7-5, while Ana Ivanovic upset 16th-seeded two-time winner Svetlana Kuznetsova 6-2 6-3.
Russian Maria Kirilenko, the 2005 winner, beat German Julia Goerges 7-6 (11-9) 6-3.
Austrian Tamira Paszek booked the first of the third-round places with her defeat of Czech Petra Cetkovska 1-6 6-4 6-2.
While seventh seed and former Roland Garros champion Francesca Schiavone of Italy went out to Slovak Dominika Cibulkova 6-2 6-2.
