Duffy's game-winner came almost one year to the day of his only other walk-off hit on May 10, 2015, against Miami. His hit followed losing pitcher Justin Miller giving up back-to-back walks, then striking out Joe Panik with one out.
"We were down to our last pitcher, so it's hard to get a bigger hit than the one Duffy got," San Francisco manager Bruce Bochy said."
Giants starter Johnny Cueto dominated the Rockies, as usual -- extending his scoreless-innings streak against them to 18 1/3. Cueto pitched around eight hits, with three strikeouts and a walk, and threw 8 1/3 innings.
"I think you have to start with Cueto because their guy [Rockies starter Jon Gray] was really on," Bochy said, crediting Cueto first among Saturday's key factors. "... So you need your guys to put up zeros, and what a game Johnny had. He pitched out of those jams."
Gray, a rookie, held the Giants to one hit and fanned five in seven innings before being removed for offense. Gray, who displayed a 96-mph fastball, but used his slider and curve more than in previous outings, has retired 35 of the last 39 batters he's faced, but has had just one run of support in his last 17 2/3 innings. Manager Walt Weiss said Gray did "not much left" after 89 pitches.
MOMENTS THAT MATTERED Regretting the hit-and-run: Sensing not much offense would happen against Cueto, the Rockies called a hit-and-run after Nolan Arenado's fifth-inning leadoff walk. But Gerardo Parra swung through a pitch and catcher Buster Posey threw out the less-than-speedy Arenado. Parra and Mark Reynolds would single, but Cueto would maneuver LeMahieu into a double-play grounder.
"He threw a nasty pitch, high, and I tried to get contact," Parra said. "It's not easy. He controlled the zone today."
For the love of Lopez: Lefty reliever Javier Lopez entered the 12th with two outs and runners on first and second. He induced a groundout by Charlie Blackmon to preserve the tie. Lopez has not been charged with a run in his last 10 appearances.
"The bullpen, what a great job they did picking each other up," Bochy said."
Estevez coming of age: Righty reliever Carlos Estevez, who pitched in Class A and Double-A last year and began this year in Triple-A, has quickly grown into a key bullpen member. Weiss called on him with Kelby Tomlinson at second in the bottom of the ninth. Estevez walked Duffy to end an eight-pitch at-bat, but worked Posey into a grounder to third.
"I didn't think that we were going to use me like this, right away in my career, but it's a good feeling," said Estevez, who on Friday threw Posey a first-pitch slider and on Saturday retired him on a first-pitch fastball. "They trust you and put you in that situation. It's great to have that confidence they give me."
Almost doesn't count: The Giants were that close -- twice -- to making crucial defensive plays and preventing the Rockies' lone run in the 10th inning. With one out, center fielder Denard Span dove and missed LeMahieu's liner to right-center for a triple off reliever Gearrin. Wolters followed with a grounder down the first-base line just past the diving Belt to give the Rockies a 1-0 lead.
"Good bounce-back by the club. The way they pitched, the way they played. … You're going to have those games. It's all about bouncing back. They've played well that last couple of games." -- Bochy, on the Giants removing the sting of a 13-run inning suffered against these same Rockies in Thursday's loss
Blackmon singled to open the Rockies' fourth, but Cueto erased him with a pickoff. He was called safe, but Bochy challenged, and the call was overturned. Cueto retired the next two hitters.
With two outs in the 13th inning and Arenado on first, Parra grounded to a diving Panik, who hooked the ball to Crawford covering second for a close play. Parra was called safe, but the Giants challenged, and the call was overturned, much to the appreciation of the AT&T Park crowd that had lessened in size but remained engaged. More>
WHAT'S NEXT Rockies: Righty Eddie Butler (0-1, 6.75 ERA), who retired the first 11 Padres in his last start before struggling to a loss, will face the Giants in the series finale on Sunday at 2:05 p.m. MT. The Giants and Rockies will use pink bats and other pink gear in support of breast cancer awareness.
Giants: Right-hander Jeff Samardzija (4-1, 3.32 ERA) takes the mound for San Francisco to face the same Rockies team that he beat to get his first victory in a Giants uniform. The right-hander is 3-0 with a 2.06 ERA in eight career appearances against Colorado. First pitch is scheduled for 1:05 p.m. PT.