Argentina's Agustin Gallardo tries to get the ball past German pair Jan Kolakowski and Julian Hoyer ©FIVB

Czech Republic delivered a major shock at the International Volleyball Federation Boys' Under-19 World Championship, defeating defending champions Iran in straight sets in Tunisia.

At Salle Polyvalente Radès in Tunis, Matous Drahonovsky top scored with 17 points as the Czech Republic bounced back from a loss to Italy in Pool B.

They recorded a 25-17, 25-17, 25-22 victory to climb to second in the pool behind the Italians.

Italy remain undefeated, courtesy of a 25-28, 25-19, 25-13 win against Colombia.

Cuba won a third consecutive Pool A match with a 25-18, 17-25, 25-19, 25-20 triumph over Chinese Taipei.

Jose Gutierrez top scored with 18 points as Cuba dominated the match.

Brazil had to fight back to win the first set against hosts Tunisia, before easing to a 27-25, 25-17, 25-14 victory.

Korea's Joung Han-yong has a shot blocked by Roman Murashko, Mikhail Fedorov and Ilya Kazachenkov of Russia ©FIVB
Korea's Joung Han-yong has a shot blocked by Roman Murashko, Mikhail Fedorov and Ilya Kazachenkov of Russia ©FIVB

It was a first win of the tournament for the six-time youth world champions, who had lost their opening match against Cuba.

In Pool C, Egypt were made to fight hard for a third win from three games, against Japan.

Japan fought back from 2-0 down to level at 2-2 before the north Africans cruised through the final set for a 25-19, 25-20, 23-25, 15-25, 15-10 triumph.

Argentina fell to a first defeat of the championship as Germany sealed their first win in Pool C, thanks to a 25-21, 22-25, 25-20, 25-21 scoreline.

The 2016 under-16 silver medallists Russia won 22-25, 25-21, 25-18, 25-23 against South Korea to remain unbeaten in Pool D, as the United States won 25-22, 25-19, 25-20 against Nigeria.