On Friday night, the 22-year-old right-hander became the first pitcher from Taiwan in the major leagues, in a 7-3 win over the Milwaukee Brewers. The game was broadcast live in Taiwan, Rockies spokesman Billy Witter said, and nearly 20 Taiwanese reporters had media credentials.
Tsao allowed three runs and eight hits before being replaced with one out in the seventh inning. He received a standing ovation from the home crowd and high-fives from his teammates.
"Giving up the home run didn't mean too much to me. It's just important that a young kid got to go out and pitch and get to start," said Brad Siebrasse, 22, a fan from suburban Lakewood.
During the game, several fans waved mini Taiwanese flags.
"Our country has been pushed around by China. This is a nonpolitical situation we can wave our flag in and China can't do anything about it," Jason Chen, 31, of suburban Englewood said before the game.
Fans behind Colorado's dugout held up "K" signs each time Tsao struck out a batter. He finished with five strikeouts and one walk.
Tsao (whose full name is pronounced chin way sow) was called up from Double-A Tulsa on Tuesday after Denny Neagle was placed on the 15-day disabled list with an elbow injury.
Tsao signed a contract with the Rockies in 1999 that paid a $2.2 million bonus. He underwent "Tommy John" elbow surgery two years later, but he went 11-4 with a 2.46 ERA and a Texas League-high 125 strikeouts this season.
Coors Field in Denver is the same ballpark where Dodgers outfielder Chin-Feng Chen last September became the first major league player from Taiwan.
The play of Chinese center Yao Ming of the Houston Rockets has helped draw many Asian -- and American -- fans to NBA games.
Paul Lin's wife tutored Tsao in English when he first arrived in Denver.
"For Taiwanese kids, I think it might spark some interest to find out more about Taiwan if they've forgotten about it," said Lin, who was born there. "It brings out the name 'Taiwan' to a lot more people out here."
Chinese-born Guo Ping Li has been to only one other baseball game, but that could soon change.
"Holy smokes! That means I'm going to every game," Li said. "I am a very big basketball and football fan, not a very big baseball fan. Now I guess I have to."