Vladimir Nikolov added 21 points as Bulgaria downed Russia 25-21, 23-25, 25-22, 22-25, 15-12 to improve to 7-2. Russia dropped to 8-1.

The top three teams in the 12-nation tournament will qualify for the Beijing Olympics.

"It was a difficult game so we are really happy to win it," said Kaziyski. "Before this match we thought we had very little chance to qualify for the Olympics, but now we have won we feel we have more hope."

Elsewhere, Brazil improved to 8-1 with a 25-20, 25-22, 25-16 victory over Argentina.

After losing their first match of the tournament 3-0 to the United States, the reigning Olympic and world champions have won eight straight without dropping a set.

Brazil faces Russia on Saturday.

"We have to play much better tomorrow and control their power and serve and try to use our speed," said Brazil coach Bernardo Rezende.

The United States kept its hopes of qualifying alive and improved to 7-2 with a 25-18, 27-25, 25-19 over Japan (3-6).

William Priddy scored 16 points for the U.S. and Gabe Gardner added 15.

Honolulu's Clay Stanley (Kaiser High, University of Hawai'i) was used as a substitute server in the first and second games.

"After the two days off our team was able to get back into a pretty good rhythm," said U.S. coach Hugh McCutcheon. "Once we settled down into a good service rhythm and got some block and defence going we played pretty well."

The Americans will face Argentina and Russia in its final two matches.

Puerto Rico, lead by Hector Soto and Jose Rivera, defeated Tunisia 25-17, 25-17, 25-23 to improve to 5-4. Tunisia dropped to 1-8.