LONDON — After two days of gloom and doom, Japan’s Kaori Matsumoto burned brightest in the women’s judo 57-kilogram weight class Monday, giving the nation its first gold medal of the London Olympics.
Matsumoto led Japan’s women judoka to their first medal in London and the brightest of them all with a victory over Corina Caprioriu, albeit by disqualification for an illegal throwing technique by her Romanian opponent.

Japan’s Riki Nakaya, meanwhile, had to settle for the silver after losing to Russia’s Mansur Isaev in the men’s 73-kg final.

The 24-year-old Matsumoto, making her Olympic debut, became the first Japanese woman to win an Olympic gold in this category.

“I knew that when I won this gold medal it wasn’t just me that won it. I had to fight for all of the people who have supported me,” said Matsumoto, who is known for the penetrating stare she shoots at her opponents as she engages in battle.

“It really gave me strength to have all those people rooting for me. I am happy that I could be No.1 (to get Japan’s first gold medal),” she said.

The reigning world champion struggled to get a grip on Caprioriu’s judo-gi, pushing the match into the golden score extra period after her yuko point in regulation was disallowed by the judges.

But Caprioriu used an illegal maneuver when she attempted to sweep out Matsumoto’s pivoting foot, automatically disqualifying her for the dangerous move.

“There is only one representative for the country. It makes hearing the national anthem a totally different experience. I cried when I won, so I have no more tears left. I remembered a lot of struggles to get here, but I was determined not to let anything ruin my focus,” Matsumoto said.

In the semifinals, Matsumoto had a rough-and-tumble battle with France’s Automne Pavia, as she was unable to get her left-hand inside grip on her opponent’s lapel throughout regulation, forcing the match into the golden score.

But she kept up the pressure as Pavia grew weary and had to rely on a right-handed grip to send her opponent to the mat with a major outside trip after 44 seconds to secure the first judo medal for Japan’s women at these Summer Games.

Things started badly for Nakaya in the final against Isaev, and only got worse. The Russian put the reigning world champion in an arm lock early in the match, apparently hurting Nakaya’s right elbow. Isaev later scored a yuko when he countered Nakaya’s scooping throw to earn the decisive points.

The 23-year-old Nakaya was aiming to become the first Japanese judoka to win the title in the category since Kenzo Nakamura won gold at the 1996 Atlanta Games in what was then the 71-kg class.

“I was representing Japan, so I was determined to get the gold, but I see that I am still missing something. My goal was to bring home the gold medal, so I’m not too happy about this medal,” said Nakaya.

In his semifinal, the Ehime native had few chances to win the struggle for hand position against Dex Elmont of the Netherlands, but won a unanimous judges’ flag decision after an oxygen-draining eight minutes due to his rival’s passivity. Elmont was the same opponent Nakaya beat in the final of the 2011 world championships.

Japan’s men won their third medal after Hiroaki Hiraoka’s silver in the 60 kg and Masashi Ebinuma’s bronze in the 66 kg.

Tomoko Fukumi (48 kg) finished in fifth on the opening day, while Misato Nakamura (52 kg) crashed out in her first match against eventual gold-medal winner An Kum Ae of North Korea.