SAN FRANCISCO -- Colorado Rockies rookie sensation Trevor Story had a historic month of April.

Five days into May, he played a part in team history as well.

Story homered to trigger the highest-scoring inning in franchise history Thursday night, as the Rockies erupted for 13 runs in the fifth en route to a 17-7 victory over the San Francisco Giants in the opener of a four-game series.

"It's been a whirlwind. A lot of fun," Story said of the first five weeks of his major league career. "The wins and the team records are the ones I'm most proud of."

Nolan Arenado belted a two-run homer, his 16th in just 54 games against the Giants, and Gerardo Parra drove in three runs with three hits, helping Colorado win for the fifth time in the first seven games of a 10-game trip.

Two of Parra's hits and all three of his RBIs came in the fifth, during which the Rockies recorded the highest-scoring inning in AT&T Park history.

Colorado's previous mark for an inning was 12 in the eighth against the Chicago Cubs on July 30, 2010.

"We knew coming in that it's kinda hard to get runs in this park," Story said. "But it's not like we were hitting home runs all the time. We were hitting line drives all over the park."

The record-breaking inning came at the expense of Giants starter Matt Cain (0-4), who failed to win for a 13th consecutive start dating back to last season.

The right-hander became just the second San Francisco pitcher in the last 20 years go 13 straight starts without a win. Barry Zito endured the same drought in 2013.

"He just couldn't get out of it," Giants manager Bruce Bochy said of the 13-run fifth. "You hate to have it happen at home. Man, it's tough to see."

The 13 runs in the fifth were three more than the previous high in the 16-year history of AT&T Park.

The Giants were less than a week removed from having watched the Mets score 12 runs against them in the third inning last Friday night in New York. They became the first team in major league history to surrender 12 or more runs in an inning two times in a seven-day stretch.

Story and DJ LeMahieu also had three hits apiece for the Rockies, who recorded their highest run total in a game at AT&T Park. Their previous high was 15 on Sept. 24, 2008.

"Whenever we come in here, it's never normal," Rockies manager Walt Weiss said. "The last three days, it was tough for us to score. You never know. Not a whole lot surprised me anymore."

Story, Parra and Arenado each had three RBIs for Colorado, which had 10- and 11-run outputs when it won two of three from the Giants at Coors Field in April.

The homer was Arenado's 12th of the season. He had six in nine games at AT&T Park last season.

Story went deep for the 11th time.

Carlos Gonzalez and Mark Reynolds each contributed a double and a single to the 17-hit attack. Gonzalez, who scored three runs, has hit safely in 23 of his first 27 games.

"It's not easy to get hits. It's not easy to score runs," said Charlie Blackmon, who contributed an RBI double to the big inning. "It's nice to get a bunch together. I'm impressed with our at-bats that inning."

Right-hander Christian Bergman (1-3) picked up the win in relief of Rockies starter Chris Rusin, who failed to make it out of the fifth inning despite being staked to a 17-3 lead.

Denard Span had two doubles and a single for the Giants, who were opening a seven-game homestand.

Matt Duffy also had three hits, including a double, and Buster Posey and Gregor Blanco drove in two runs apiece for San Francisco, which totaled 16 hits.

The Giants fell to 3-9 this season in games started by Cain and Jake Peavy.

"We know we have to get better there," Bochy said of his fourth and fifth starters. "Matty would tell you the same thing. Same thing with Jake. Right now they're our guys, so we're staying behind them."

The Giants' defense fell apart in the fateful fifth, helping lead to Cain's demise.

Shortstop Brandon Crawford and second baseman Kelby Tomlinson made errors early in the 13-run explosion, prolonging an inning that could have been over seven batters into it.

Story's homer came on Cain's fourth pitch of the inning to increase the Colorado lead to 5-3.

Then the roof caved in on the Giants.

Parra's first hit of the inning, an RBI single, followed a throwing error by Crawford on a grounder hit by Arenado.

That ended Cain's night before he got anyone out in the fifth. He was charged with eight runs (six earned) on 10 hits. He had neither a strikeout nor a walk, just the second time in 297 career starts that he failed to record a strikeout.

Right-hander Vin Mazzaro replaced Cain and retired only one of the 10 batters he faced. Tomlinson's error on a grounder by Reynolds began the reliever's nightmare.

Tony Wolters had a two-run double and Parra a two-RBI single against Mazzaro, who gave up nine runs on six hits and also hit Arenado with the bases loaded.

Rusin capped the historic inning with a two-run single off the Giants' third pitcher, right-hander Derek Law, giving the Rockies a 17-3 lead.

NOTES: The Rockies never previously scored more than nine runs in a single inning in a road game. ... The top of the fifth inning took 37 minutes. The entire inning lasted 59 minutes. ... The Giants played without three regular starters -- RF Hunter Pence (sore back), 2B Joe Panik (strained groin) and LF Angel Pagan (strained hamstring). Giants manager Bruce Bochy indicated before the game that Pence and Panik were likely to return Friday. ... The Rockies also did some lineup juggling in the series opener, scratching C Nick Hundley just before first pitch and inserting C Tony Wolters. Hundley said he tweaked his left oblique during batting practice. ... The Rockies and Giants, both in the bottom six in the National League in ERA, are both expected to be represented at RHP Tim Lincecum's showcase in Arizona on Friday. The 31-year-old, a former two-time Cy Young Award winner, went 7-4 with a 4.13 ERA last season for the Giants and is currently a free agent.