Rockies manager Jim Tracy quipped, "They had an extra infielder -- they should have brought in an extra outfielder."
The victory over the National League West-leading Dodgers (17-8) pulled the Rockies (12-12) to .500, gave the Rockies 2-of-3 in the series, and no doubt lifted a club that isn't guaranteed victory no matter how many dramatic moments it provides.
Giambi's homer, on a day when Carlos Gonzalez went deep twice and rookie Wilin Rosario also homered off Dodgers lefty stalwart Clayton Kershaw, certainly prevented the current nine-game homestand -- 3-3 going into a weekend series with the Braves -- from becoming a study in frustration.
On Sunday, Todd Helton's grand slam in the eighth tied the Mets, 4-4, Gonzalez homered in the 10th, and yet the Rockies lost. On Tuesday, the Rockies fell behind the Dodgers, 7-0, but came back and had the tying run at third base when Gonzalez struck out on pitches in the dirt.
This time, Gonzalez's eighth-inning shot off Kershaw gave the Rockies a 5-3 lead, only to see that disappear.
With two out and one on in the top of the ninth, manager Jim Tracy asked closer Rafael Betancourt (1-0) to intentionally walk Dodger stalwart Matt Kemp - the National League Player of the Month for April -- putting the tying run on base. Dee Gordon then made the Rockies pay with a two-run double, and handed Betancourt with his first blown save in seven tries.
"if I had the decision to do over, I'd have done it the exact same way," Tracy said. "I certainly would not have slept well tonight if in fact I would have let Matt Kemp hit and he hits the ball out of the ballpark. If they were going hit a homer in that situation, Dee Gordon's going to have to do that, not Matt Kemp.
"That's not on Rafael Betancourt. That's on me. It didn't work out."
A Rockies ninth inning that started with Eric Young Jr. and Marco Scutaro drawing walks from reliever Jamey Wright (1-1) and moving on Jonathan Herrera's bunt set up Giambi's winner.
Gonzalez, whose presence on deck in the ninth forced Elbert to go after Giambi, was fighting off frustration. In the Rockies' last nine games, Gonzalez is 14-for-34 (.412) with all seven of his home runs, 18 RBIs and 12 runs scored. Yet, the Rockies entered Wednesday just 1-3 in games in which Gonzalez has homered.
"I was having that feeling after they scored two runs in the ninth inning," Gonzalez said. "At the same time, there's always another opportunity, especially playing at home. I was ready to take another at-bat. I didn't get the chance because Giambi got the nice hit."
It was the first homer of the season for Giambi, but he tends to heat up at this time of year, with Interleague Play approaching later this month. Last year, Giambi had one homer in April but eight combined in May and June.
"It's a dream spot to be in with CarGo [on deck]," Giambi said. "It makes it a tough decision for people. You're not really out of the woods walking me right there. You just load the bases for CarGo."
"He got a good pitch to hit and did what he's supposed to do," said Elbert. "He got me."
Rockies left-handed rookie starter Drew Pomeranz went a career-high 6 2/3 innings and gave up one run on four hits, with five walks and four strikeouts. Kershaw allowed five runs on seven hits -- including the three homers -- in 7 1/3 innings.
The Rockies needed a big performance from Pomeranz to spell a tired bullpen. Pomeranz had suffered left forearm tightness and left his last start early, but displayed a lively fastball that he sometimes cut to his glove side. He broke several bats.
"Honestly, I didn't think I had my best stuff, but that's pitching," Pomeranz said. "I had a lot of movement on my fastball and was jamming a lot of guys."
The Rockies' Rex Brothers gave up a single to Andre Ethier with one out in the eighth to put runners at the corners, wild pitched Ethier to second and yielded Jerry Hairston two-run double for a 3-2 Dodgers advantage.
However, workhorse reliever Esmil Rogers, who has appeared in five of the Rockies' last seven games and warmed up in the other two, struck out James Loney and forced A.J. Ellis to pop out.