SAN FRANCISCO -- Matt Cain finished his first major-league outing and immediately headed to the video room to review one notable at-bat.
Colorado's Todd Helton fouled off eight straight 3-2 pitches in a 14-pitch at-bat in the fifth inning before flying out to left on Cain's 103rd and final pitch.
"I made some really good pitches at the end," Cain said.
And some really good pitches at the beginning, too.
"He has electric stuff, the kind of stuff you don't see very often," Giants catcher Mike Matheny said of Cain.
Holliday connected off Cain for his 14th homer leading off the second, and Byung-Hyun Kim (4-10) earned his first road win in seven starts this season. He gave up two runs and three hits in eight innings, struck out six and didn't walk a batter for just the second time this season.
"I felt the best tonight of any start," Kim said. "I am making progress and looking forward to next year."
Brian Fuentes worked the ninth for his 25th save in 28 chances. He established a franchise record for saves in a season by a lefty, passing Bruce Ruffin's mark of 24 set in 1996.
At 20 years, 332 days, Cain became the youngest Giants pitcher to make his first big league start since Mark Grant on April 27, 1984, at Cincinnati (20 years, 185 days).
The hard-throwing right-hander (0-1), San Francisco's top pitching prospect, allowed two runs and three hits, struck out two and walked four. Moises Alou hit a solo homer to left-center in the fourth, his 15th, but the Giants managed little else.
Getting through the challenge from Helton should be a "confidence builder," Giants manager Felipe Alou said.
"He made a nice first impression," Colorado skipper Clint Hurdle said. "That was solid stuff. And he put a cherry on top with that confrontation with Helton."
Asked what he will most remember when he looks back on this much-anticipated day, Cain said "probably all of it."
"Every single part of it was a great moment for me," he said. "Hopefully I can cherish it and save it for as long as possible."
He'll have help doing that.
Cain's parents, Tom and Delores, were in town from Tennessee, and his personal pitching coach, former major-leaguer Mauro Gozzo, also was in the stands along with Cain's high school coaches from the Memphis area.
"You think when he gets drafted in the first round that it's going to happen, but you don't ever think it's going to happen this quick," said Lane McCarter, Cain's coach at Houston High in Germantown, Tenn.
Cain is the second-youngest current player in the majors behind 19-year-old pitching phenom Felix Hernandez of the Seattle Mariners.
Cain threw only nine pitches in the first inning: 94 mph ball, 95 mph strike, 95 mph ball, 95 mph strike for the first out; struck out Luis Gonzalez on a 96 mph fastball; then got Helton to fly out to left on a 96 mph fastball.
But on Cain's 10th pitch, the first of the second inning, Holliday sent a 94 mph fastball deep into the left-field bleachers.
"He welcomed me to the big leagues," said Cain, who then walked Garrett Atkins before getting six straight outs.
Cain realized even the pitchers at this level are a threat. Kim had a 10-pitch at-bat in the second.
"I even respect what Byung-Hyun Kim can do with the bat," Cain said.
Though the hype has been huge, Cain never showed any signs of the pressure getting to him.
He loaded the bases with no outs in the fourth on a walk and two singles, but got Dustan Mohr to ground into a double play that allowed a run to score. Cain gave up another walk, but struck out Danny Ardoin looking to get out of the inning without further damage.
"I think he's doing great," Gozzo said. "That was a great inning for him, his first pressure inning in the big leagues with the bases loaded and no outs. One thing, he's got to keep his pitch count down. At 20 years old, he's a phenomenal talent."
Cain calmly watched TV before the game, then later joined some fellow pitchers for cards.
"We hung out last night and all day today," lefty reliever Jack Taschner said. "About 1 o'clock, his whole attitude changed and he got a lot more serious."
The Giants demoted struggling right-hander Brett Tomko on Friday and brought up Cain, whose talents have been touted ever since San Francisco selected him 25th overall in the first round of the 2002 draft.
Cain became the Giants' 11th starting pitcher of the year and 13th rookie. ... The Giants recalled OF Jason Ellison from Triple-A Fresno to take the roster spot of Michael Tucker, traded Saturday to the Philadelphia Phillies. ... RHP Jamey Wright was moved to the bullpen so Colorado can take a serious look at its young pitchers. Manager Clint Hurdle met with Wright, who handled the news well. "I pulled him in and talked to him," Hurdle said. "We had a nice conversation. I had a script to follow, but I just threw it away." ... Kim beat the Giants for the first time in three career starts.