DENVER — Nolan Arenado completed the cycle with a three-run homer in the bottom of the ninth inning, and the Colorado Rockies stunned the San Francisco Giants by rallying for a 7-5 victory Sunday.
Arenado hit the first pitch he saw from All-Star closer Mark Melancon (1-2) into the left-field seats to finish a four-game sweep. The slugger was mobbed at home plate by teammates, with a frenzied sellout crowd chanting "MVP! MVP!"
With the best record in the National League, the surprising Rockies have won five straight overall and nine in a row against the Giants.
Colorado had a 3-2 lead in the top of the ninth but gave up three runs before scoring four in the bottom half.
Pinch-hitter Hunter Pence connected on a go-ahead homer in the ninth for last-place San Francisco, which has dropped six consecutive games and nine of 11.
Melancon retired his first batter, but three singles produced a run and brought up Arenado, who tripled in the first, singled in the fourth and had an RBI double in the sixth. He hit a 91 mph fastball for his 15th homer and first career cycle.
It was his second game-ending homer in the majors and the eighth cycle in club history.
Carlos Estevez (4-0), called up from the minors before the game, struck out one batter in the ninth for the win.
Trevor Story and Pat Valaika went deep in the seventh to give Colorado a 3-2 edge after Brandon Crawford's two-run homer in the fifth had given the Giants a 2-0 advantage.
Rockies reliever Jake McGee came on in the ninth but issued a one-out walk to Gorkys Hernandez. Pence hit an 0-1 fastball into the left-center seats for his third career pinch-hit homer, and Crawford added an RBI single later in the inning.
Giants: LHP Madison Bumgarner (left shoulder) is scheduled to throw a second simulated game in Arizona on Wednesday. He threw his first Saturday, the first time he faced hitters since getting injured in a dirt bike accident in Colorado in April.
Rockies: RHP Chad Qualls was placed on the 10-day disabled list with lower back spasms. The move is retroactive to Friday. ... Rockies RHP Chad Bettis threw 15-20 fastballs during a bullpen session, continuing his comeback from treatment for testicular cancer. Bettis, who finished chemotherapy this month, had been throwing off the mound to a catcher in front of the plate. Sunday was the first time he threw the full 60 feet, 6 inches.
Rockies second baseman DJ LeMahieu showed why he won the NL Gold Glove in 2014 with a great play to save a run in the first inning. LeMahieu was moving to cover second after Crawford broke from first when Buster Posey hit a grounder toward the vacated spot. LeMahieu reached back to field the ball and tossed it to Story while sitting on the infield. Story stepped on second to start the inning-ending double play. Crawford was initially called safe at second, but the Rockies challenged and the call was overturned.
Giants: RHP Johnny Cueto (5-6, 4.57 ERA) opens a four-game series at Atlanta on Monday.
Rockies: RHP German Marquez (5-3, 4.19 ERA) starts the opener of a key three-game series with Arizona on Tuesday.