The loss dropped the Giants to two games behind the Rockies in the National League Wild Card race and 6 1/2 behind the NL West-leading Dodgers. Earlier in the day, Los Angeles blanked Chicago, 2-0. The five-run margin was also the largest lead the Giants surrendered this season. San Francisco is currently 5-4 on its 11-game road trip.
The opening act began when Giants answered the Rockies' first-inning run, responding in the second when Bengie Molina doubled and scored two batters later on Aaron Rowand's RBI single to left. The tie was short-lived, as Nate Schierholtz launched Jorge De La Rosa's belt-high slider for a two-run homer into the Rockies bullpen in right.
Garko extended the Giants' lead to 5-1 in the third when he crushed De La Rosa's 2-1 slider into the left-field seats for his first home run as a member of the Giants. Garko held the bat high, stared at the flight of the ball for a second, then flung the bat toward the Rockies dugout and raced down the first-base line.
The Giants had a five-run lead in the top of the fourth when Randy Winn singled to drive in starting pitcher Joe Martinez, who had reached on a single and advanced to second on a wild pitch. Martinez collected his first Major League hit in the second inning on a ground-rule double to left.
"Hopefully, there are going to be more hits," Martinez said. "It's nice to have that baseball, but if not, it's not the biggest deal in the world. I hope whoever got it is happy with it."
As quickly as the Giants took their big lead, they handed it right back. The Rockies scored two runs in the fourth to trim the deficit to 6-3, and then they erupted in the sixth.
Martinez served up back-to-back singles to begin the sixth and was knocked out when Ian Stewart drove the right-hander's 93-mph up-and-away fastball to left to tie the game at 6. Justin Miller relieved Martinez, but he didn't fare much better.
After retiring his first batter, Miller gave up a single to Yorvit Torrealba, then pinch-hitter Seth Smith lined an RBI triple down the right-field line, scoring Torrealba as the go-ahead run. Garko dove and missed for Smith's liner, and after he landed on his belly, Garko turned his head and looked on as the ball rapidly rolled further away from him.
Miller retired only one of the six batters he faced. Three Rockies reached against Miller on extra-base hits, including Todd Helton's mammoth solo homer, which forced Miller out of the game.
In all, the Rockies scored seven runs, had seven hits and sent 11 men to the plate in the sixth. That frame tied a season high for runs and hits allowed by Giants pitchers in an inning. The Angels accomplished the same feat in the fourth inning on June 15 at AT&T Park.
It wasn't much better in the seventh, as the Giants bullpen gave up four walks in a four-run inning to trail, 14-6. All of the runs in the inning were charged to Merkin Valdez.
Between the bottom of the fourth and the end of the seventh, the Giants were blitzed for 13 runs.
"The team that I've been managing since the 29th of May showed up in about the fifth inning," Rockies manager Jim Tracy said. "I know the type of baseball team we've had since the end of May, and for the first game and a half of this series, it wasn't that team. But the last half of this game, it is the team that I've been managing."
The Giants bullpen, which entered the game ranked first in the Majors with a 3.34 ERA, surrendered eight runs, six hits and six walks in three innings.
"I can't just go get guys if I'm going to run out of pitching," Bochy said. "[Miller has] done a good job. I hoped he got out of it. We were stretched out as it was.
"This is a park where you can't just go get your pitcher any time. You have to be a little more patient. You'll go through your 'pen there real quick. Both sides have been using their 'pens. You've got to stay with them a little bit longer and hope they figure it out. I can't bail everybody out or I'm going to run out of pitchers."
Miller (2-2) took the loss, as he surrendered four runs on four hits. Martinez took a no-decision, as he gave up six runs (five earned) on nine hits in five-plus innings. He threw only 73 pitches and felt that if he had pitched well, he could've last longer and spared the bullpen.
"It's not a question of how I felt," Martinez said. "Obviously, I wasn't performing up to the standard that I should. It wasn't a question of how I felt. I felt fine."
De La Rosa (12-8) earned the win, as he yielded six earned runs on eight hits in six innings. He has won 10 of his past 11 decisions.
The lone bright spot was Garko and the offense. Of the Giants' 12 hits, nine were for extra bases, including a season-high five homers. Garko added an eighth-inning blast to secure his third career multihomer game and his second this season. The last time the Giants sent that many balls out of the park was on Aug.7, 2006, when they had six at Arizona.
"It's not about individual stuff right now," Garko said. "It's about winning games. You'd trade anything just for a win."