Last year's runner-up Marin Cilic was a first-round loser, while rising American Sam Querrey posted a come-from-behind victory Monday at the $2.2 million China Open.
Unheralded Romanian wild card Marius Copil ousted the fourth-seeded Croatian Cilic 3-6, 7-6 (7-0), 6-4 on the hardcourts at Beijing's National Tennis Centre, which hosted the Olympic tennis event in 2008. Cilic lost despite uncorking 21 aces.
Cilic was a Beijing runner-up in 2009 and last year, when he gave way to Czech Tomas Berdych in the final.
Meanwhile, Querrey advanced by upsetting eighth-seeded Spanish left-hander Fernando Verdasco 5-7, 6-3, 6-4 and sixth-seeded Ukrainian Alexandr Dolgopolov avoided an upset by handling Spaniard Guillermo Garcia-Lopez 6-0, 6-4 on Day 1.
Additional wins came for Argentine Carlos Berlocq, German Florian Mayer, Chinese wild card Ze Zhang, and South African Kevin Anderson, who overcame American qualifier Brian Baker 5-7, 6-3, 6-1.
On Tuesday in Beijing, top-seeded two-time champion Novak Djokovic will face German Michael Berrer; second-seeded 2010 runner-up David Ferrer of Spain will tangle with Taiwan's Yen-Hsun Lu; third-seeded Frenchman Jo-Wilfried Tsonga will meet Uzbekistan's Denis Istomin; and fifth-seeded Frenchman Richard Gasquet will play Aussie Matthew Ebden. Gasquet is fresh off his first title in more than two years last week in Bangkok.