The Russian Olympic Committee's team improved to 2-0 in men's volleyball when it held back a spirited Team USA comeback on Monday.
The United States, led by Matt Anderson, entered the match off a 3-0 defeat of France but found itself down 2-0 after 25-23 and 27-25 sets.
The Americans snapped into the match with a spirited 25-21 win in the third set and looked set to force a fifth when it opened up a 19-15 lead on the ROC in the fourth.
But the Russian Olympic Committee's team rallied to get 10 of the next 14 points available and claimed a 25-23 win.
Taylor Sander joined Anderson in leading the Americans with 14 points won each, but Russia had three players in double digits: Dmitry Volkov, Egor Kliuka, and Maxim Mikhaylov.
The Americans will next face Tunisia before matches with Brazil and Argentina.