By Jimmy Golen

Associated Press

BOSTON — Even the man who built the Red Sox into a World Series champ was amazed by the greeting Daisuke Matsuzaka got at Fenway Park.

“Wow,” gasped Boston general manager Theo Epstein as he faced a relentless battery of camera flashes, illuminating Fenway’s premium club packed with 300 reporters and photographers.

It was a wild day, both for Matsuzaka and for Boston.

The 26-year-old right-hander wrapped up a whirlwind 24 hours in his new baseball home Thursday night, meeting the U.S. and international media at a news conference after agreeing to a six-year, $52 million deal with the Red Sox. Boston Mayor Tom Menino stood by; Epstein even put on a suit.

“We know that many of you have traveled great distances to be here today, and we very much appreciate it,” Epstein said. “This is like the signing of a national treasure. … We understand his importance. We know what he represents.

“To the fans in Japan, we pledge to do everything that we can to support Daisuke, to assist him and his family and to ensure that he will be a success. Not that he needs much help.”

Epstein paused for his remarks to be translated to Matsuzaka and the Japanese reporters. Matsuzaka dutifully held up his new jersey — No. 18, just like Johnny Damon used to wear — but hesitated to put his Boston cap over his neatly spiked hair. The cameras flashed and flashed.

To accommodate the media throng, the news conference was moved from the regular interview room, where beat writers more typically ask David Ortiz what pitch he hit for a game-winning homer. Timed for the live 5 p.m. newscasts in Boston — and the 7 a.m. shows back in Japan — Matsuzaka’s words were beamed worldwide by 16 TV satellite trucks lined up on Van Ness street, along the first-base line.

“This is a great day not only for Red Sox fans but for fans of major league baseball,” Red Sox chairman Tom Werner said. “The excitement at Fenway Park in 2007 will really be ratcheted up another level. I think Daisuke will provide a great number of stories for many years to come for us.”

NESN, the television station owned by the Red Sox and Bruins, scheduled an 18-hour “Matsuzaka Marathon” on Thursday. On Friday night it scheduled a replay of the championship game of this spring’s World Baseball Classic; Matsuzaka won that game for Japan and was named the tournament’s Most Valuable Player.

That will be the first opportunity for many Red Sox fans to see him pitch. But Japanese Prime Minister Shinzo Abe has seen plenty: Matsuzaka won Japan’s high school championship, pitched in two Olympics and was the MVP of the inaugural World Baseball Classic this spring.

“(Matsuzaka) is Japan’s best pitcher, and his ability was fully evaluated,” the prime minister said, adding that he was “so impressed” by Matsuzaka after learning of his new contract.

The Red Sox handed out T-shirts that said “B is for baseball,” with “baseball” written in Japanese. Upstairs in the press box dining room, there was a reception offering hot dogs, Yankee pot roast and sushi.

“Both American cuisine and Japanese cuisine,” Red Sox spokesman Charles Steinberg said.

Although the Fenway grass is covered and fenced off because of offseason construction, Matsuzaka got a tour during the afternoon and threw a ceremonial pitch from the mound to owner John Henry. “I put down four fingers expecting a changeup, but he crossed me up,” Henry said.

Later, Matsuzaka headed off to drop the puck at Bruins game. The cheers echoed down Yawkey Way as his car rolled past Fenway.