SAN FRANCISCO -- A 13-run inning one night. A 13-inning game two days later.

It's obvious which the pitching-strong San Francisco Giants prefer.

Matt Duffy doubled in Conor Gillaspie with two outs in the bottom of the 13th inning Saturday, lifting the Giants to a 2-1 victory over the Colorado Rockies in a 4-hour, 20-minute marathon.

"My girlfriend and I are meeting her parents for dinner at 7 (p.m.) in Antioch," Duffy said of a destination about an hour east of San Francisco. "I had to get a hit there."

The game-winner came at 5:25, giving Duffy the luxury of squeezing in a shower before rushing out the door.

"A lot of guys try to end it with one swing early in extra innings," Duffy said in discussing his second career walk-off hit. "The at-bats get better the longer the games go."

The win was the Giants' second in four extra-inning games this season and was their second straight over the Rockies after having watched the visitors put up 13 runs in a historic fifth inning Thursday night in a 17-7 drubbing.

Colorado fell to 0-2 in extra innings, with the games having gone 12 and 13 innings.

Gillaspie, pinch-hitting for pitcher Derek Law, drew a one-out walk from the seventh Rockies pitcher, right-hander Justin Miller (1-1).

After Miller also walked Denard Span, he struck out Joe Panik before Duffy hit a liner to deep left field that eluded Rockies outfielder Gerardo Parra, who spun completely around and then had the ball land about 10 feet away.

"The ball moved a lot," Parra explained. "The weather was not ideal, but that's baseball."

Law (1-0) posted his first major-league win by pitching a scoreless top of the 13th, allowing one walk.

After neither team scored for nine innings, and both stranded the potential winning run in the ninth, each scored in the 10th.

Tony Wolters rolled a double past a drawn-in infield, scoring DJ LeMahieu, who had tripled, to give the Rockies a 1-0 lead in the top of the 10th.

The hits came against the Giants' third pitcher, right-hander Cory Gearrin.

But Colorado closer Jake McGee couldn't hold the lead, surrendering a leadoff triple to Brandon Belt and an RBI single to Brandon Crawford in the bottom of the 10th.

"A lot of good play on both sides," summed up Rockies manager Walt Weiss. "They got the big hit at the end."

The blown save was McGee's second of the season.

The game had begun as a pitchers' duel between right-handers Jon Gray of the Rockies and Johnny Cueto of the Giants.

Weiss pulled Gray after seven one-hit innings in a 0-0 tie. Gray had thrown 89 pitches.

The Giants' only hit off Gray was a leadoff single by Span in the fourth. He eventually was stranded at second base, the only baserunner to reach scoring position for the Giants until the ninth.

Gray, whose career high for pitches thrown in a game is 92, walked one and struck out five. He received a no-decision, running his career-opening streak of games without a win to 13, the longest in franchise history.

"There were a lot of quick innings and guys made plays behind me," Gray noted. "It was a pretty good day for pitchers."

The Rockies have scored a total of 12 runs with Gray on the mound in his last 10 starts. They scored 13 runs in one inning earlier in the series with left-hander Chris Rusin pitching.

Cueto pitched into the ninth, then left after back-to-back, one-out singles by Trevor Story and Carlos Gonzalez put the potential go-ahead run on second base.

Right-hander Santiago Casilla pitched out of the jam, retiring Nolan Arenado on a foul out to catcher Buster Posey and Parra on a grounder to first baseman Brandon Belt.

Cueto, who was seeking his fifth win of the season, allowed eight hits in 8 1/3 innings. He walked one and struck out three.

"We couldn't get anything going offensively," Giants manager Bruce Bochy observed, "so you need your guy to go out there and put up 0's. What a great game."

Duffy and Belt had two hits apiece for the Giants, who were out-hit 12-7.

Story, Parra, LeMahieu and Charlie Blackmon had two hits apiece for Colorado.

NOTES: The walk-off win was the Giants' second of the season. ... Giants RHP Johnny Cueto extended his scoreless-innings streak at AT&T Park to 20 1/3. He hasn't allowed a run to the Rockies since Aug. 15, 2014, a stretch of 18 1/3 innings. ... The seven innings pitched by Rockies RHP Jon Gray were a career-high. ... Neither team took batting or infield practice on the field before the game because of a light rain that did not impact the starting time of the contest. ... Rockies C Todd Hundley (strained left oblique), who was injured during batting practice Thursday night, has been placed on the 15-day disabled list. The Rockies promoted C Dustin Garneau from Triple-A Albuquerque to fill the roster spot.