DENVER (AP) Nolan Arenado and Carlos Gonzalez did their part in a comeback. The bullpen did not.
Buster Posey hit a pair of three-run homers, including a tiebreaking drive as part of a six-run eighth inning, and the San Francisco Giants rallied for a 10-5 win over the Colorado Rockies on Saturday.
The Rockies were 19-0 when ahead after seven innings this season. Now, they're 19-1.
''I like the way we came back,'' Rockies manager Walt Weiss said. ''Just couldn't stop them from scoring.''
This was another wild one at Coors Field in a game that featured both bullpens blowing late leads, with a combined 11 relievers being used, and lots of late scoring.
''You figure you're going to have some back-and-forth games, some long games here,'' Posey said.
This one didn't disappoint.
The Rockies were limited to one run over six innings by starter Madison Bumgarner, but erupted in the seventh against five San Francisco relievers.
Arenado had a two-out, two-run double in the seventh and Gonzalez followed with a towering, two-run homer to center that gave the Rockies a 5-4 lead and sent the more than 39,000 fans in attendance into a frenzy.
That was soon silenced as the Rockies bullpen imploded.
Carlos Estevez (1-2) gave up singles to Joe Panik and Matt Duffy to start the eighth before Posey delivered a three-run shot.
''You have to have a short memory,'' Estevez said, who only faced three batters and didn't record an out. ''You fail and tomorrow you may get a chance again and you have to be ready for your team.''
In all, the Giants sent 10 batters to the plate in the pivotal inning and had eight hits.
Posey also hit a three-run homer in the first inning off Eddie Butler. It was the third multihomer gamer of Posey's career, two of which have now come against the Rockies. His six RBIs tied a career best.
Cory Gearrin (1-0) threw 1 1-3 scoreless innings to earn his first win since May 28, 2013. He also had his first major league hit.
''We needed somebody to calm things down. He did a great job,'' manager Bruce Bochy said.
There was some encouraging news for Colorado as struggling starter Jorge De La Rosa had an effective performance out of the bullpen. Making his first relief appearance since July 12, 2009, De La Rosa allowed two hits and no runs in two innings.
''Build up his confidence and build him back up,'' Weiss explained. ''He had the slow start, he missed some time, so have some small successes before he goes back out there and tackles the game as a starter.''
Bumgarner was at his best in the sixth inning when he escaped a bases loaded, no-out jam by striking out Ryan Raburn and getting Cristhian Adames to hit into a double play. That kept a 4-1 lead in tact.
''I can't say enough about what Bum did today. What a gutty effort,'' Bochy said. ''He willed his way through that sixth inning. What a jam he was in.''
Only, the Giants bullpen couldn't hold the lead, either.
''It's exciting to come from behind, and Buster to have a huge day,'' Gearrin said. ''It was a good win.''
Rockies: 2B DJ LeMahieu received the day off. Manager Walt Weiss plans to give some of his regulars a breather over the next week.
Rockies reliever Adam Ottavino threw about ''120 mph'' in a live batting practice session Saturday as he recovers from Tommy John surgery. At least, that was the velocity according to longtime Rockies great Vinny Castilla, who stepped in to face the Ottavino.
''He was nasty,'' said the 48-year-old Castilla, who hadn't seen major league pitching since 2006 and managed two foul balls off Ottavino. ''He looks great.''
Ottavino said he was ''letting it go'' in the 21-pitch session. He will throw another few batting practice sessions before heading out for a rehab assignment.
Giants: RHP Johnny Cueto (7-1) hasn't allowed a run in the last 18 1-3 innings against the Rockies - a streak he will try to extend Sunday.
Rockies: LHP Chris Rusin (1-2) will start Sunday as he takes the place Jorge De La Rosa in the rotation. De La Rosa was recently sent to the bullpen.