He came in to pitch in the bottom of the ninth inning, and after retiring Edgardo Alfonzo and John Olerud, struck out Mike Piazza and got the save in the Diamondbacks' 8–7 victory over the New York Mets.
On June 9, 1999, during a game against the Chicago Cubs, a bandage covered in a foreign substance fell from Kim's sleeve after a pitch.
With Mantei reinserted as the closer, Kim pitched as a setup man and also started a game after recording 84 relief appearances.
He made his first career postseason appearance in the NLDS Game 3 at Busch Stadium to protect the Diamondbacks’ 5–3 lead against the Cardinals with the go-ahead run at the plate in the 8th inning.
Kim pitched masterfully in the inning, ending the bases loaded jam with a double play and a lineout.
The next night, Kim pitched another two shut-out innings and earned the two-inning save that clinched the Diamondbacks’ ticket to the World Series.
But Paul O'Neill hit a single off Kim before Williams' plate appearance and Tino Martinez's two-out, two-run home run tied the game in the bottom of the ninth inning.
With another home run hit off Kim by Jeter in the bottom of the tenth, the Yankees won the game and tied the Series.
When Matt Mantei returned from the disabled list and became the Arizona Diamondbacks' closer, Kim joined the starting rotation.
On June 27, Kim made his final start for the 2003 season in Boston's 25–8 win against the Florida Marlins at Fenway Park.
Kim became the Red Sox closer in July, converting 16 out of 19 save opportunities despite pitching through lingering ankle and shoulder pain caused by the injury he sustained in April.
Although he did not give up an earned run in September, by the time the postseason started Kim was not healthy enough to be effective on the pitching mound.
Thinking that he did not deserve the booing after he pitched despite being in pain to advance the Red Sox to the postseason, Kim gave them the middle finger, but later issued an apology.
[10] Before the 2005 season, the Red Sox sent Kim to the Colorado Rockies, with general manager Theo Epstein calling the two-year deal given to him in 2004 "a mistake."
Kim was traded for left-handed pitcher Chris Narveson, who was optioned to Triple-A Pawtucket, and catcher Charles Johnson, who was immediately designated for assignment and released.
They became the first two pitchers with same last name to start both ends of doubleheader since Gaylord and Jim Perry for the Cleveland Indians in 1974.
Kim represented Korea in the World Baseball Classic, a tournament held during spring training before the 2006 season.
Kim was credited with solid shutout middle relief performances during the tournament in Korea's wins against Taiwan in the first round and Japan[15] and the United States.
In the semifinal game against Japan, Kim relieved Jun Byung-doo in the 7th inning and then allowed a two-run home run to Kosuke Fukudome.
On May 22, 2006, Kim and his former high school teammate and then-Los Angeles Dodgers' starter Jae Seo started against each other.
In four different starts, he recorded nine strikeouts each against the Florida Marlins, Houston Astros, Pittsburgh Pirates and Washington Nationals.
[citation needed] Kim began the 2007 season with the Colorado Rockies as a reliever after he lost his starting rotation spot to Josh Fogg.
Kim contended that he was not given a fair opportunity during Spring training to compete for a starting spot and asked to be traded.
Kim was concerned that his rehab assignment was longer than necessary and changed his agent to Scott Boras in an effort to get a quicker trade.
[22] On August 1, Kim collected his 50th career win with a career-high ten strikeouts in his starting matchup against Colorado Rockies' Josh Fogg.
Kim's return to Arizona lasted two starts; the Diamondbacks designated him and Joe Kennedy for assignment on August 14.
On January 25, Kim signed a one-year deal with the Tohoku Rakuten Golden Eagles of the Nippon Professional Baseball (NPB).
[35] On January 18, 2012, it was announced that Kim signed a one-year deal with the Seoul-based team the Nexen Heroes of the KBO League.
[citation needed] In 2014, Hall of Famer, and perennial award-winning third baseman Adrián Beltré named Kim as the toughest pitcher he had ever faced, due in large part to his pitching motion.