So while China won't be able to duplicate its sweep of all 10 diving golds from the 2011 worlds in Shanghai, Russia remains on target to sweep all seven titles in synchronized swimming again.
Svetlana Kolesnichenko and Svetlana Romashina were flawless to the tune of "Michael Forever," the Michael Jackson tribute, winning the duet technical with 97.300 points. Romashina opened the synchro competition Saturday by winning the solo technical.
Chinese twins Jiang Tingting and Jiang Wenwen took silver with 94.900 and Ona Carbonell and Margalida Crespi gave Spain their second consecutive bronze with 93.800.
Germany may not have pulled off the most spectacular dives at the Montjuic Municipal pool with its views of Barcelona's skyline crowned by the Sagrada Familia basilica. But Klein and Hausding avoided the slips-ups that cost their main rivals gold and took full advantage of their opportunities when China and Mexico appeared to let the moment get the better of them.
After a polished display in qualifying in the morning session, China was favored to maintain its dominance of an event in which it had won at the past three Olympics as well as the last three worlds.
But a poor performance by Cao and Zhang left them playing catch-up to finish third on the winners' stand, meaning the Asian country has now won medals in this event in all eight editions since its inclusion at the 1998 worlds.
Hausding said he would "be lying" to say that beating the Chinese wasn't an "upset."
"Of course it is good for us to have beaten the Chinese, but nevertheless everyone was very strong: the Russians, the Cubans," he said.
China led early until a bad entry on the fourth dive cost it the lead to the resurgent Mexican pair of German Sanchez and Ivan Garcia, who finished second behind them at the 2012 London Games.
Then it was Mexico's turn to fail to execute a reverse tuck with 3 1/2 somersaults in the fifth and penultimate round. Sanchez and Garcia finished fourth in front of the surprisingly strong Cuba pair of Jose Guerra and Jeinkler Aguirre
Klein and Hausding then hit a reverse pike with 3 1/2 somersaults in the final round. But they could only celebrate after China's final dive, worth a whopping 99.36 points, was not enough to overtake them or the Russians.
Klein said it wasn't until Mexico's blown fifth dive that he could savor the gold.
"It was after the fifth round, everyone was making great dives, and then some of the divers made a mistake," Klein said. "It reminded me of two years ago when we made a mistake. We talked about it and then had a really good last dive."
Cao said he and Zhang had done the best they could.
"We feel that throughout this tournament we have prepared ourselves physically," Cao said. "The most important thing for us is that we did our best."
Also in diving on Sunday, China's He Zi led qualification for the women's 1-meter springboard.
He, who won gold in the women's 1-meter springboard at the age of 16 at the 2007 worlds, collected the highest score for Tuesday's final through five dives for a total of 287.70 points. She was followed by Italy's Tania Cagnotto with 284.85 points.
China's Wang Han was right behind in third with 284 points. She is also well placed to medal after winning a silver and a bronze in 1-meter springboard from the previous two world championships.