If only his tiebreaking homer would've sealed the win as tight.
No such luck. Not here at Coors Field, where big leads can shrink oh so rapidly.
Pacheco gave the team a seemingly safe cushion in the fifth, Carlos Gonzalez later added an insurance homer and the Colorado Rockies weathered a late rally by the San Francisco Giants for a 10-9 win on Friday night.
With that, the Rockies snapped a 10-game skid against the Giants.
Sure, it was just one win, but it was a big one for the Rockies' psyche.
"It's obvious we've had some rough history against the Giants," manager Walt Weiss said. "It's just nice to be able to fight back and, in the end, put a game away."
It would be far from easy.
The Giants, who rallied from an early six-run deficit the night before, were on the comeback trail again Friday.
Down five, they made things interesting by scoring three times in the seventh. It could've been more, but Dexter Fowler made a diving catch in center to end the inning.
"Game changer," Weiss said.
After Buster Posey made it a 10-9 game in the eighth with a two-out homer off Matt Belisle, Hunter Pence followed with a double. But Belisle got Brett Pill to ground out and strand Pence.
In the ninth, Rafael Betancourt struck out the side for his 10th save in as many chances.
"That's a tough-guy save right there, because the game was pretty crazy," Weiss said.
Pacheco laced his first homer of the season to left on a hanging slider from Madison Bumgarner (4-2), who failed to protect an early four-run lead.
"Felt good," Pacheco said with a modest shrug.
Fowler had a feeling it might be a big night for Pacheco, who was filling in for Todd Helton at first base. They took early batting practice together and the ball was flying off Pacheco's bat.
"I saw the thump he had," Fowler said. "So that (homer) didn't surprise me."
Jorge De La Rosa (5-3) entered the game without giving up a run at Coors Field in 12 innings. He was hit hard, surrendering five runs in five innings, only to settle down enough to earn the win.
Gonzalez, Troy Tulowitzki and Wilin Rosario—the heart of the Rockies' batting order—finished with a combined six hits, four RBIs and five runs scored. Gonzalez added an insurance run with his homer in the sixth.
"Huge win," Gonzalez said. "This team is tough to beat."
Pablo Sandoval had three hits and drove in two runs for San Francisco, while Marco Scutaro extended his hitting streak to 16 games.
Bumgarner turned in his first clunker against the Rockies in quite a while. He had won six of his last seven starts before struggling on Friday. The lefty allowed a season-high nine runs—seven earned—in just 4 2-3 innings. His ERA climbed nearly a full run to 3.09.
Trying to preserve a one-run lead in the fifth, Bumgarner gave up a game-tying single to Rosario. A walk to D.J. LeMahieu loaded the bases for Pacheco, who sent the first pitch from Bumgarner over the fence.
"That grand slam wasn't too fun," Bumgarner said. "I just wasn't making pitches when I needed to (in order) to get guys."
Pacheco also had an RBI on a grounder in the second.
"Just glad I was able to come through for our team," he said.
The Giants had a frightful night in the field, committing a season-high four errors. Two of those miscues came in the third, when Sandoval had a throwing error to begin the inning and center fielder Angel Pagan later sent a high throw to third base that ended up in the Giants' dugout, allowing Dexter Fowler to trot home. Tulowitzki tied the game at 4 with an RBI single.
"Too many errors, particularly in this ballpark," manager Bruce Bochy said. "They fought back, I'll say that. But we're making way too many errors.
"We've got to tighten things up."
The Giants have made themselves quite comfortable at Coors Field, winning 14 of their last 20 in this hitter's park. Weiss quickly dismissed the notion the Giants have a psychological edge on his team.
Although, this does help.
"We know we've got to beat these guys," Weiss said. "We know they've had our number over the last couple of years. They're the world champions, so you have to go through them eventually. We know all that stuff. It's not stuff we have to talk about, it's already there. Got to go out and play well, find ways to win games."
NOTES: Giants RHP Tim Lincecum (3-2) will start Saturday night. ... The hot-hitting Scutaro is batting .485 during his streak. ... San Francisco is 31-10 against Colorado since 2011. ... The Rockies altered their starting rotation, with RHP Tyler Chatwood getting the start on Saturday and RHP Juan Nicasio being bumped back to Sunday. Chatwood joined the team from Triple-A Colorado Springs on Friday and will be added to the roster before his start.