China is perfect on the diving board and the medals podium.

The world’s diving superpower completed a sweep of the synchronized events, winning the men’s 3-meter springboard and putting China halfway toward taking all the gold medals.

The Chinese also won the men’s 10-meter platform and women’s 3-meter and 10-meter synchro golds.

‘‘I think Chinese divers have done a great job so far,’’ Qin Kai said through a translator. ‘‘We have four golds now and they all came with perfect performances.’’

Qin and partner Luo Yutong led all six rounds of the final, totaling 477.00 points. It was Qin’s second straight springboard synchro title, having won the event four years ago in Beijing with a different partner.

Kristian Ipsen and Troy Dumais of the United States earned the bronze at 446.70.

It was the first medal of Dumais’s long career in his fourth Olympics, equaling Greg Louganis for most appearances by a male US diver. The 33-year-old Californian finished fourth in the event at the 2000 Sydney Games partnering with his brother Justin. They missed out on a medal after botching their last dive.

‘‘This medal is also for my brother. I thought about him,’’ said Dumais, who finished sixth in Athens. ‘‘Things happen the way they’re supposed to happen. I wouldn’t be the athlete that I am if I gave up.’’

Dumais’s coach, Matt Scoggin, said, ‘‘He still had that fire in him when a lot of people would have retired. It took longer than he wanted, but arguably it was worth the wait.’’

After a 12-year medal drought, the Americans won a silver and two bronzes in three of the four synchro events. They didn’t qualify in women’s 10-meter platform.

Ipsen, an Olympic rookie, put pressure on himself to make sure Dumais earned a medal this time.

‘‘He said, ‘Don’t even think about it, let’s just have fun and the result will come’ and it did,’’ Ipsen said. ‘‘I helped him achieve one of his dreams. It feels even better.’’

Kayak

The Italian powered down the white water course at Waltham Cross, England, to win the men’s kayak slalom on his 28th birthday.

Molmenti finished 1.35 seconds ahead of Vavrinec Hradilek, who gave the Czech Republic its first medal of these games. Germany’s Hannes Aigner won bronze.

Molmenti added Olympic gold to his 2010 world championship and a trio of European titles.

Fencing

‘‘I guess I'm just in disbelief,’’ Zagunis said.

With good reason — the face of US fencing and the American flag bearer at the opening ceremony last week not only was denied a third straight gold medal, but she’s going home without any medal at all.

Zagunis dropped her last two matches in the women’s sabre event, after wasting a 12-5 edge over Kim Jiyeon of South Korea during a 15-13 semifinal loss. Not long afterward, and still reeling, Zagunis gave up nine of the final 11 points to fall, 15-10, to Olga Kharlan of Ukraine in the bronze bout.

For Zagunis, it was an unimaginable fate.

‘‘Even now, it’s all pretty surreal,’’ Zagunis said.

It was a double-dose of coming close for the Americans, who won six medals in fencing in Beijing. Seth Kelsey lost the bronze-medal match in men’s epee to South Korea’s Jung Jinsun, 12-11, in extra time.

Kelsey walked away from the piste with no regrets, after never before winning an Olympic individual match. Zagunis left in a far different mindset.

South Korea’s Kim went on to win the women’s sabre gold over Russia’s Sofya Velikaya, while Ruben Limardo of Venezuela took the men’s epee gold-medal match against Bartosz Piasecki of Norway.

Judo

She defeated German Kerstin Thiele in a tense final in the 70-kilogram category of judo — a match marked by aggressive grabbing and pulling that sometimes resembled a schoolyard fight.

Decosse won a silver at Beijing and is a three-time world champion. She dropped to the mat on her back clutching her face after winning and had to be coaxed to her feet by the referee for the official announcement that she had won.

Song Dae-nam of South Korea won the men’s 90-kilogram division, adding to the country’s judo haul. South Korea already had won one gold and one bronze.

Song defeated Cuban Asley Gonzalez in a closely contested final that went into overtime. Both players were on the defensive for much of the bout, until Song used speedy footwork and dropped low to give him an edge in throwing Gonzalez for the win.

Shooting

Kim finished with 792.4 points, beating defending champion Chen Ying of China by one point.

Olena Kostevych of Ukraine won bronze.

Table tennis

Gold-medal winner Li Xiaoxia called it her ‘‘dream since being a little girl,’’ but she was mostly subdued after her upset victory over teammate Ding Ning.

She raced to the stands to get a Chinese flag and waved it for a few moments, but the celebration didn’t last long. Afterward, she was short with emotional words and kept the stern, serious face she had while playing Ding.

‘‘Today I performed better than expected,’’ she said. ‘‘I would like to thank my parents. They have sacrificed a lot to make my dreams come true.’’

Asked when she would celebrate, she said it would have to wait until after the upcoming team competition. After that? ‘‘I don’t know. I haven’t thought about it,’’ she said.

Ding was the emotional one — talkative, upset, and pleading her case.

Usually upbeat and open, Ding cried afterward and suggested Italian referee Paola Bongelli may have cost her a gold medal.

Weightlifting

Lu Xiaojun smashed two world records (for snatch at 175 kilograms and 379 kilograms in total) in the most emphatic victory yet in the weightlifting competition. His teammate and compatriot Lu Haojie was a distant second. Ivan Cambar Rodriguez of Cuba won bronze.

The man who denied China its ninth gold medal in nine attempts in Beijing — Sa Jae-hyouk of South Korea — was injured in the snatch as his right arm buckled at the elbow. He left the competition and was taken to hospital for a checkup.

Rim Jong Sim won North Korea’s third weightlifting gold in London as she clinched the women’s 69-kilogram class in a dramatic finish.

Sim lifted a total weight of 261 kilograms but was challenged until the end by silver medalist Roxana Cocos of Romania.