Brazil beat Poland in straight sets on Wednesday to cruise into the semi-finals of the Olympic men's volleyball tournament.

Brazil marched toward the Olympic medal contention with their fifth victory, 25-22, 27-25 and 25-18, in a high-profile clash between two volleyball heavyweights.

Poland got off to an early lead in the first set with 4-1 and 9- 5. But the Brazilians soon geared up with a 4-0 run and caught up at 14-14. A serve error by Piotr Cruszka of Poland gave Brazil the set point at 24-22 before Andre Nascimento closed the set with a wonderful spike.

The second set went point by point. Poland reached the set point by Brazilian Ricardo Garcia's fault serve. But Andre Heeler and Gilberto Godoy Filho stepped up to tie the score and have two blocks as they sailed to a tight 27-25 win.

The last set was much easier for Brazil as led by Heller, Brazil produced a 5-0 run to take the score to 13-7 and a spike from Godoy Filho concluded the victory for Brazil.

Godoy Filho led the Brazil team with 15 points, Nascimento had 14 and Dante Guimaraes Amaral had 11.

Gruszka scored 18 points to lead Poland, Sebastian Swiderski added 9.

Brazil's blocking played a decisive role as they overwhelmed their rivals 9-4 in the one hour 23 minutes games.

Brazil will face the United States at the semi-finals. The latter defeated host Greece 3-2 (25-20, 22-25, 25-27, 25-23, 17-15) early on Wednesday with a tremendous comeback.

After trailing 1-2 in the first three sets, the Americans were behind 12-20 in the fourth. But the United States produced an unbelievable 9-1 run to tie the score at 21-21 and finished with 25-23.

The Americans then repeated the scenario in the fifth after Greece led 12-9. They came from behind to reach the match point 16- 15. Sotirios Pantaleon of Greece could not convert his spike over the net and let the Americans win the two hours 16 minutes match.

Kevin Barnett led the American team with 20 points, William Priddy added 16.

Antrei Kravarik contributed to the host team 26 points and captain Marios Gkiourdas had 17.

Following are the Olympic men's volleyball tournament results on Wednesday:

Quarter-finals

Russia bt Serbia Montenegro 3-1 (29-27, 23-25, 27-25, 28-26)

Italy bt Argentina 3-1 (22-25, 25-22, 26-24, 28-26)

United States bt Greece 3-2 (25-20, 22-25, 25-27, 25-23, 17-15)

Brazil bt Poland 3-0 (25-22, 27-25, 25-18)

Semifinal fixtures:

United States vs Brazil, Russia vs Italy.