China manager Lefebvre was ejected during the game
Jake Arrieta struck out seven and Taylor Teagarden and Nate Schierholtz hit two-run doubles as the US beat China 9-1 in the Olympics baseball.
But there were three ejections for China, with manager Jim Lefebvre one of those dismissed for arguing against what he perceived to be rough play.
John Gall added an RBI double in the Americans' three-run fifth and Terry Tiffee hit his sixth Olympics double.
South Korea beat Taiwan 9-8, while Japan recorded a 1-0 win over Canada.
As well as Lefebvre, China relief pitcher Chen Kun and pitching coach Steven Ontiveros were also ejected.
Tempers had flared after the host nation's catcher Wang Wei, who is on the books of Major League side Seattle Mariners, was knocked out of the game following a collision at the plate with Matt LaPorta.
Back-up catcher Yang Yang had to be held back from Schierholtz after the American made a hard slide home, leading to Lefebvre's ejection.
After US manager Davey Johnson and Ontiveros were called out to discuss the increasingly heated game with the umpiring crew, Chen then hit LaPorta on the head with a pitch at the start of the seventh innings - causing Chen and Ontiveros to be tossed.