Host nation China took its first gold medals of the 2008 Olympics on Saturday, winning in weightlifting and sharing shooting honours with the Czech Republic, dpa reported.
Spanish cyclist Samuel Sanchez continued Spain's golden sporting year with gold in the gruelling men's road race, and Mariel Zagunis led a US women fencers' clean sweep in the individual sabre.
Chen Xiexia won the women's 48 kilos weightlifting competition to the delight of 6,000 fans in the packed Beijing University of Aeronautics and Astronautics Gymnasium.
She put China on a path it hopes will lead to a record haul at its home Games, with a 600-plus team that might even beat the US for first place in the final medals standings.
The 2007 world champion lifted 87kg in the snatch and 117kg in the clean and jerk for an Olympic record of 212kg, beating Sibel Ozkan of Turkey into second place. Bronze went to Taiwan's Chen Wei-Ling.
"I have been thinking about winning a medal but I never thought it would turn out to be the first gold medal for China. I am very happy and I did a good job," said Chen.
Her victory compensated for an earlier disappointment for China in the women's 10 metres air rifle shooting, where the 2004 gold medallist Du Li had to settle for fifth place.
Katerina Emmons of the Czech Republic won the event to capture the first gold of the Games, with Lioubov Galkina taking silver for Russia and Snjezana Pejcic of Croatia grabbing the bronze.
"Now I have achieved the very best, everything that I could get. Especially since it's my first gold at the Olympics it feels amazing," said Emmons, who received the gold medal from Olympic supremo Jacques Rogge.
Emmons, 24, equalled the world record 400 rings in the qualifying round and never looked back in the 10-round final, adding 103.5 for a total 503.5 rings.
In the men's 10 metres air pistol, China's Pang Wei put in a commanding performance to give his country its second gold. Silver went to Jin Jong Oh from South Korea, with North Korea's Kim Jong Su taking bronze.
Samuel Sanchez added his name to an ever-growing list of Spanish worldbeaters when he took gold in the men's road cycling race at the Great Wall near Beijing, edging out Italy's Davide Rebellin in a sprint finish involving six riders. Switzerland's Fabio Cancellara claimed bronze.
"I think we can say that Spain is going through something of a golden age in sport at the moment," said Sanchez. "We won Euro 2008, Rafael Nadal is the number one tennis player in the world and we have got NBA basketball players like Pau Gasol and Jose Calderon."
Mariel Zagunis's sabre gold, her second after the Athens Olympics, led an historic fencing medal sweep for the United States - the country's first in fencing and only the second in women's fencing after the West German foil success led by Anja Fichtel in 1988.
Zagunis, 23, beat Sada Jacobsen 15- 8 in the gold medal tussle with Rebecca Ward assuring the sweep by coming back from 11-8 down to beat Russia's Sofiya Velikaya of Russia 15- 14 in the bronze medal bout.
"It is absolutely amazing. We made history today. I am proud of myself as well as Sada and Becca," said the elated Zagunis. "I wanted a gold medal. I wouldn't care if it is my first or last. It is mine."
In judo, 2003 world champion Choi Minho of South Korea floored reigning European champion Ludwig Paischer of Austria with a decisive ippon throw to clinch gold in the men's 60-kilos category.
Choi had required just four seconds to beat Dutchman Ruben Houkes in the semi-finals while Paischer advanced to the gold medal match over Rishod Sobirov of Uzbekistan.
Earlier, four-time reigning European champion Alina Dumitru of Romania also won inside the full distance as her ippon after 1:20 minutes against Yanet Bermoy of Cuba clinched the women's 48kg gold. Paula Pareto of Argentina and Japan's Ryoko Tani took bronze.
The swimming - which sees the finals all held in morning sessions beginning Sunday - got under way with American star Michael Phelps leading a group of favourites in the first heats session.
Phelps, who is going for an unprecedented eight gold medals at the competition, comfortably won his heat in the 400m individual medley in a new Olympic record time of 4:07.28.
Hungarian Lazlo Cseh had the second-fastest time, while Luca Marin of Italy was third. Phelps' friend Ryan Lochte, whom many believe to could stop Phelps making history, qualified with fourth fastest time.
In the women's 100m butterfly Australian Libby Trickett, who is the current world champion, had a narrow escape as she qualified for the semi-finals in 12th place.