BEIJING — The U.S. men's volleyball team could have been broken by tragedy. Instead, they stand undefeated and one step closer to an Olympic medal.

The men beat Bulgaria 3-1 on Thursday night, overcoming a cold start to take the next two sets and hold off the Bulgarians in the end 27-29, 25-21, 25-14, 26-24 in round-robin pool play.

The United States is the only undefeated team in its pool, and the win was a key step in advancing to the quarterfinals.

Clay Stanley, a Kaiser High and University of Hawai'i alum, led the United States with 18 kills, 2 blocks and an ace.

Stanley was clear about the team's goal.

"A medal. We want to play as hard as we can. We focus on every game so we can reach the medal round," he said. "I've told people every time our goal is to win a medal. We're not here just to show up."

"It's not going to be easy. It is going to be hard," middle blocker Ryan Millar said. "It's the Olympics. It's supposed to be hard."

The U.S. adjusted after dropping the first set, finding ways to stop Bulgarian spiker Matey Kaziyski. Stanley's spike was the second set winner.

Bulgaria became frustrated in the third, and even coach Martin Syoev at one point slumped in his chair, shaking his head. Todor Aleksiev threw up his hands when his team missed what should have been an easy return.

Trailing for most of the fourth set, Lloy Ball's key block late turned the momentum for the United States.

"I think we're starting to realize our potential," wing-spiker Reid Priddy said. "I think some things we do really well, and when we don't do something really well, we're able to figure it out and still win."

Kaziyski had 18 for Bulgaria, whose record is now 2-1.

The men's volleyball team has won in Beijing even as they grieve the death of coach Hugh McCutcheon's father-in-law, Todd Bachman, who was killed last Saturday during a visit to the 13th-century Drum Tower, a popular Beijing tourist site. His mother-in-law was badly wounded before the assailant jumped to his death.

McCutcheon's wife is the Bachmans' daughter, Elisabeth "Wiz" Bachman McCutcheon, who played for the U.S. women's team in the Athens Olympics.

He left to team to be with his family, and it is not known when he will return. Assistant Ron Larsen is serving as interim head coach.

On Wednesday, U.S. Olympic Committee spokesman Darryl Seibel said Barbara Bachman remained in a Beijing hospital in serious but stable condition.

Bulgaria remained without captain Plamen Konstantinov, who was temporarily removed from the team amid rumors of doping. Konstantinov returned to Bulgaria to take an independent test.

The chairman of Bulgaria's anti-doping commission has said Konstantinov did not fail any doping test.

"His blood showed high levels of testosterone and, although they were below the maximum admissible levels, the volleyball federation decided to take an extra precaution and remove him from the match," Kamen Plochev told National TV earlier this week. "In their panic, the federation made a hasty decision."

Konstantinov has missed all three of his team's Olympic matches.

There are 12 men's teams competing in Beijing, divided into two pools. The top four teams will emerge from round-robin play into the quarterfinals.

In earlier games Thursday, Italy defeated Venezuela 3-0 (25-21, 25-20, 25-21), Germany defeated Egypt 3-0 (29-27, 25-21, 25-21), Poland defeated Serbia 3-1 (31-29, 22-25, 25-22, 25-21) and China defeated Japan 3-2 (25-20, 25-23, 17-25, 16-25, 15-10).

Russia defeated top-ranked Brazil 3-1 (22-25, 26-24, 31-29, 25-19). Brazilian wing-spiker Giba played only briefly because of a sore shoulder.