Phil Dalhausser and his partner, Nick Lucena, defeated the Austrian team of Robin Seidl and Alexander Huber late Saturday in the knockout stage of men's beach volleyball.
The U.S. pair won in straight sets, 21-14, 21-15.
With the win, Dalhausser and Lucena advance to the quarterfinals.
The Americans beat an Italian duo -- Daniele Lupo and Paolo Nicola -- 21-13, 21-17, 24-22 on Thursday night to finish unbeaten in group play.
The third set in a beach volleyball match is supposed to be up to 15 — but the team has to win by 2. The Italians fought off a half-dozen match points before the Americans nailed it down.
Dalhausser won gold in Beijing and finished ninth in London with Todd Rogers, while Lucena is an Olympic rookie.
The No. 2 U.S. men's team of Jake Gibb and Casey Patters was eliminated on Wednesday after going 1-2 and losing the playoff tiebreaker.