Spain shocked United States at the FIBA 3x3 World Championships ©FIBA

Two-time defending champions United States suffered a shock 21-16 women's defeat to Spain today as their unbeaten record was ended at the International Basketball Federation 3x3 World Championships at the  Tianhe Sport Complex in Guangzhou.

The US women's team had won both previous editions of the global 3x3 event in 2012 and 2014 without losing a single game.

They followed day one victories over Italy and Japan with a 17-8 triumph over Taiwan in their opening clash today.

But the Spanish proved too strong and finished 18-7 winners.

Both teams remain in pole position to qualify from Pool C along with Italy, who followed an 21-6 win over Japan with a 17-11 victory over Taiwan today.

European champions Hungary lead group B despite suffering a mixed day in a tournament taking place at a venue with a view on the iconic 600-metre tall Canton Tower.

It began well with a 14-11 win over Argentina before they slipped to a 12-11 loss against Australia.

United States continued their dominance in the men's competition ©FIBA
United States continued their dominance in the men's competition ©FIBA

Defending champions Qatar recovered from their opening day loss to Serbia by winning twice in Pool A of the men's competition today.

They first beat New Zealand 21-16 before a similarly tight 20-17 win over 2014 bronze medallists Russia.

Serbia continued their unbeaten streak in the "group of death" with 16-13 and 20-17 wins over Italy and New Zealand respectably.

United States gained two victories in Group D, over Japan 21-12 and China 21-15.

The Netherlands moved into second place with a 14-8 win over Turkey followed by a 21-12 success against Japan.

Action is due to continue tomorrow in the other four groups.

The competition is being broadcast live on the recently launched Olympic Channel.

The top two in each group will qualify for the quarter-finals.