The three top-seeded pairings were knocked out as the International Volleyball Federation (FIVB) World Tour Xiamen Open reached the men's last eight stage today.
Canada's Chaim Schalk and Ben Saxton, the top seeds, were beaten in three sets by Spain's seventh seeds Pablo Herrera and Adrian Gavira.
The Spaniards triumphed 21-17, 19-21, 15-8 and finished off their victory with a pair of aces.
"Wow, I was lucky," said Herrera.
"I pushed for that, but it was lucky.
“It’s a great match.
"They played very well.
"But we have very good side-out, very good blocking and service; I think that’s the key to our victory.”
The result assures the Spanish team of their first top four finish of the World Tour season so far.
“It’s important for us to win a medal here for the confidence, for the Olympic ranking and entry points,” said Gavira.
“We have to enjoy the semi-final, our first semi-final of the year, and we have to enjoy the match.
"No matter what comes out, we’ll be happy.”
Herrera and Gavria will meet Russians Konstantin Semenov and Viacheslav Krasilnikov for a place in the final.
The fourth seeds, now the highest ranked pair left in the competition, beat Polish qualifiers Michal Bryl and Kacper Kujawiak 21-12, 21-16.
Second seeds Aleksandrs Samoilovs and Janis Smedins of Latvia, the Xiamen bronze medallists last year, were ousted by Mexico's Lombardo Ontiveros and Juan Virgen, 21-14, 21-19.
Italy’s third seeds Alex Ranghieri and Ignacio Carambula went out to American fifth seeds John Hyden and Tri Bourne, 21-16, 21-18.
The action in China continues tomorrow.