DENVER -- Their closer finally blew his first save of the season and the Colorado Rockies squandered an eight-run lead Thursday night.

But they were able to savor their first walk-off victory of the season when Raimel Tapia singled to right field with one out in the ninth, giving the Rockies a 10-9 win over the San Francisco Giants.

"This cat's got confidence," Rockies manager Bud Black said of Tapia, who went 2-for-5 with two RBIs after going 4-for-4 with three runs scored Wednesday.

Mark Reynolds led off the ninth with a single against Hunter Strickland (1-2). With one out, Strickland pitched around pinch hitter Carlos Gonzalez, walking him on four pitches and setting the stage for Tapia.

"I feel really good in those situations when they're pitching around someone to get to you," Tapia said through a translator. "You know you have the opportunity to come up and make an impact."

The Rockies, who are 10-2 in one-run games, led 8-1 after three innings and 9-1 after the sixth -- margins that vanished when the Giants packed eight runs into the final three innings.

"Scrappy win," Rockies left fielder Ian Desmond said. "We needed that. We can't let that one get away."

The loss was the 12th in 16 games for the Giants, who are a season-high 16 games below .500. The Rockies are 7-1 against the Giants this season and moved back into first place in the National League West, one game ahead of the Los Angeles Dodgers and Arizona Diamondbacks.

The Rockies inflicted most of their damage on starter Matt Moore, who has struggled in his limited history at Coors Field.

DJ LeMahieu had his sixth career four-hit game, scored three runs and drove in two. Nolan Arenado hit three doubles and drove in four runs.

After the Giants erupted for five runs in the eighth to make it a one-run game, closer Greg Holland (1-0) took the mound in the ninth with a 1.09 ERA. He gave up a leadoff single to Austin Slater, who went 4-for-5, but struck out Nick Hundley.

Denard Span lined a single to center, sending Slater to third. Span took second on a wild pitch, causing the Rockies to draw in their infield.

Slater scored on Gorkys Hernandez's sacrifice fly, just beating center fielder Charlie Blackmon's throw and giving Holland his first blown save in 24 opportunities.

Span stole third but was thrown out at home when he tried to advance on a ball that got away from catcher Tom Murphy. The play was reviewed, and the call was upheld.

"I hesitated a split second," Span said. "I think that was the difference between me being safe and out. Once the ball got in the dirt, it seemed like the ball was closer (to Murphy). I hesitated, and then I took off."

Moore gave up a season-high 11 hits and eight runs in three innings, his shortest start of the season, but he piled up seven strikeouts -- all swinging. In four starts at Coors Field, Moore is 0-3 with a 14.73 ERA and has yielded 32 hits in 14 2/3 innings.

The Rockies pounced on Moore for three runs in the first, beginning with five straight hits. Arenado doubled home two more runs in the second. He scored on a double by Desmond, who crossed the plate on Tapia's two-out single.

Charlie Blackmon tripled home a run in the third to make it 8-1. He leads the majors with nine triples, tying his career high set two years ago.

The big lead was a boon to Rockies starter Jeff Hoffman, who needed a career-high 103 pitches to weave his way through five innings. He gave up one run and seven hits.

"Didn't have the curve," Hoffman said. "Didn't really have great command of my fastball, either. I was lucky to have any bit of a changeup because if I didn't have a changeup I would've been in a lot more trouble."

Hoffman issued two of his three walks in the second, forcing in a run when he walked Moore with the bases loaded. But shortstop Trevor Story saved two runs when he made a diving catch in short left field of Span's short fly ball.

"I was just like, 'You've got to be kidding me,'" Span said. "That's just the type of season that has been going on."

Arenado doubled home a run in the sixth, but Buster Posey cut the lead to 9-3 with a two-run homer in the seventh off Scott Oberg. The homer was Posey's ninth and only his second since May 15. He left the game after the blast with left ankle soreness.

Hundley homered in San Francisco's five-run eighth when pitcher Ty Blach delivered a run-scoring, pinch-hit single to trim the deficit to 9-5.

Jake McGee came on with two outs and runners at first and second and gave up a three-run homer to Brandon Crawford that made it a one-run game and ended McGee's scoreless streak at 14 innings. It was the Giants' first three-run homer of the season.

NOTES: Rockies C Tom Murphy (broken right forearm) was reinstated from the disabled list and went 0-for-3 with a walk in his 2017 debut. C Ryan Hanigan was optioned to Triple-A Albuquerque. ... Rockies RHP Jon Gray (left foot stress fracture) is scheduled to throw 75-80 pitches in his second rehab start Monday for Albuquerque at Sacramento. ... Rockies LHP Tyler Anderson (left knee inflammation) is scheduled to throw about 75 pitches in his first rehab start Sunday for Albuquerque at Sacramento. ... Giants LHP Madison Bumgarner (bruised ribs, left shoulder strain) is scheduled to throw to hitters Sunday for the first time since he was injured April 20. ... Giants 3B Eduardo Nunez extended his on-base streak to 29 games with a single in the seventh but then left the game with left hamstring tightness.