TOKYO -- Naomi Osaka, the 20-year-old tennis star, became the face of Japanese sporting prowess when she defeated Serena Williams on Sunday to bring Japan its first Grand Slam title. On Thursday she became the face of Nissan Motor, as the Japanese car maker sought to cash in on her sudden fame by naming her its global ambassador.

Nissan's sponsorship -- the company declined to give financial details -- is likely to be followed by many more. Companies are increasingly turning to sponsorship of sports, entertainment and the arts as a means of promoting their products. Last year the global corporate spend on sponsorship hit $62.7 billion. Osaka, suddenly one of the hottest properties in tennis after her weekend win, will have global brands fighting hard for a share in the powerful cachet of her youthful, modern, mixed-race heritage image.

But for Japanese companies, in particular, her win was "perfect timing," according to a manager at a major Japanese advertisement agency. Coming just before Tokyo hosts the Olympics in 2020, Osaka's position as "a Japanese player competing on the world stage" will be the ideal platform for Japanese businesses operating in the global market, he adds.

"It was very good ... for us," an official of Citizen Watch told the Nikkei Asian Review. The Japanese company named Osaka its first global ambassador last month, and will in the coming days promote the world-wide launch of the watch she wore during the U.S. Open final. "We will focus on foreign markets such as North America and Asia," the official said. "Osaka evolves every day. She fits our brand concept very well."

Nissan Motor announced a sponsorship deal with Naomi Osaka on Sept. 13 at its headquarters in Yokohama. (Photo by Toshiki Sasazu)

Some of Osaka's existing sponsors have already seen a payoff from her triumph. Inquiries about subscriptions at pay-television company Wowow -- which not only sponsors Osaka but has broadcasting rights for all Grand Slams in Japan -- jumped 500% on the day that Osaka won the semifinal last week, an official told Nikkei.

Yonex, her equipment supplier since 2008, saw its shares rise 11% over last week's close as of Wednesday. The company will increase production of the Ezone 98 racket, which Osaka used at the final, and has decided to expand sales of tennis gear as part of a new management plan.

Nissin Food Products, the Japanese instant noodle maker which struck a deal with Osaka in 2016, enjoyed a more modest 3% rise. But a company spokesman told Nikkei he expected the increased brand exposure to lead to higher sales.

Osaka's value as a brand has suddenly skyrocketed. "Her opportunities for media exposure will increase," said the advertising executive.

That could mean existing sponsors having to significantly increase their payments or risk losing the exposure they get from a rising global star.

Rivals are already circling, especially in Japan. Adidas' contract for her footwear expires at the end of the year. Motoi Oyama, CEO of Japanese sportswear brand Asics, said it was still "too soon after her victory" to decide whether his company would fight Adidas for the contract. But he put the price at "over 100 million yen for the shoes." Asics already sponsors 14-time Grand Slam winner Novak Djokovic.

The Nissin spokesman said that the company's sponsorship might have to be reviewed in light of the weekend's victory. The company would decide whether to continue the deal after examining the merits and potential increase in fees, he said.

Executives in the sponsorship industry estimate that Osaka could now demand three or more times her current price per contract. It has been reported that she currently earns some $1.5 million a year from her various sponsors, still a long way from the $18 million earned by her heroine and role model, Williams. But that was before the Nissan deal.

The fact that she has chosen to play for Japan may make a difference to the price she can command, given the desire of Japanese companies to find a local hero to support as the Olympic Games approach. According to Forbes' list of "The World's Highest-Paid Athletes 2018," Kei Nishikori, Japan's star male player who has yet to win a Grand Slam, earned $33 million from endorsements between June 2017 and June 2018 -- less than fellow tennis star Roger Federer's $65 million, but more than big names like Rafael Nadal, with $27 million, and this year's male U.S. Open winner Novak Djokovic, with $22 million.

"Japanese businesses right now are sponsoring Nishikori to make him a symbol for 2020," said the manager. "They may start throwing similar sums at Naomi Osaka as well down the road."

Osaka's mixed-race heritage -- which has sparked debate in Japan about whether she is truly Japanese -- is unlikely to deter local companies from wanting to profit from her success.

Her mother comes from the northernmost prefecture of Hokkaido. Her father is Haitian. Osaka was born in Japan, but moved to New York at the age of three, and speaks Japanese haltingly. In a 2016 USA Today interview, Osaka noted, "When I go to Japan, people are confused. From my name, they don't expect to see a black girl."

But the fact that "she is half-Haitian or has dark skin and can't speak Japanese too well," is of no concern, the ad manager says. Instead she could be of great value to the country's sponsors whose business is selling merchandise directed at women. So far, there are far fewer women than men among the Japanese medal contenders for the 2020 Summer Olympics.

The hope in some communities is that this may change, in part thanks to Osaka's success.

Tokyo-based tennis school VIP TOP Group has 14,000 club members, including 3,725 junior member under age 15. Club membership jumped by 1,000 in the year after Nishikori's success in 2014. A club official, says that since the retirement of Japan's last female tennis star, Kimiko Date, in 1996, young girls with ambitions to play tennis have lacked a local role model. "Nishikori's success brought us many new male members. We hope Osaka will be a new icon who can encourage young girls to start playing tennis."

Yet others who develop competitive players suggest that Osaka's background and U.S. training make her one of a kind. "It will probably be impossible to raise and train a second Naomi Osaka in Japan," said the head of a private tennis club.